Answer: brightly coloured scagliola and blue and pink lapis

Question: What original colors from the 19th century were used on the advice of Sir Charles Long?


Answer: 775 rooms

Context: The original early 19th-century interior designs, many of which survive, include widespread use of brightly coloured scagliola and blue and pink lapis, on the advice of Sir Charles Long. King Edward VII oversaw a partial redecoration in a Belle Époque cream and gold colour scheme. Many smaller reception rooms are furnished in the Chinese regency style with furniture and fittings brought from the Royal Pavilion at Brighton and from Carlton House. The palace has 775 rooms, and the garden is the largest private garden in London. The state rooms, used for official and state entertaining, are open to the public each year for most of August and September, and on selected days in winter and spring.

Question: How many rooms does the palace have?


Answer: Chinese regency style

Question: In which style are many of the smaller reception rooms furnished in?


Answer: Carlton House

Question: What house were many of the furniture and fittings brought from?


Answer: Sir Charles Long

Question: Who suggested the use of brightly coloured scagliola and blue and pink lapis?


Answer: King Edward VII

Question: Who oversaw the redecoration that used a Belle Époque cream and gold colour scheme?


Answer: Chinese regency style

Question: Smaller reception rooms are decorated in which style?


Answer: Carlton House

Question: Furniture and fittings were brought over from which house?


Answer: river Tyburn

Context: In the Middle Ages, the site of the future palace formed part of the Manor of Ebury (also called Eia). The marshy ground was watered by the river Tyburn, which still flows below the courtyard and south wing of the palace. Where the river was fordable (at Cow Ford), the village of Eye Cross grew. Ownership of the site changed hands many times; owners included Edward the Confessor and his queen consort Edith of Wessex in late Saxon times, and, after the Norman Conquest, William the Conqueror. William gave the site to Geoffrey de Mandeville, who bequeathed it to the monks of Westminster Abbey.

Question: Which river runs underneath the palace?


Answer: Edith of Wessex

Question: The site of the palace was once owned by which queen consort in the late Saxon times?


Answer: Geoffrey de Mandeville

Question: Who did William the Conqueror give the site of the palace to?


Answer: Westminster Abbey

Question: The site was passed to monks from which abbey?


Answer: Manor of Ebury

Question: The site of the palace formed part of which Manor in the Middles ages?


Answer: Eye Cross

Question: What was the name of the village that grew at Cow Ford?


Answer: Geoffrey de Mandeville

Question: Who gave the site to the monks of Westminster?


Answer: Manor of Ebury

Question: What was the name of the manor that previously existed on the site?


Answer: Sir Hugh Audley

Context: Various owners leased it from royal landlords and the freehold was the subject of frenzied speculation during the 17th century. By then, the old village of Eye Cross had long since fallen into decay, and the area was mostly wasteland. Needing money, James I sold off part of the Crown freehold but retained part of the site on which he established a 4-acre (16,000 m2) mulberry garden for the production of silk. (This is at the northwest corner of today's palace.) Clement Walker in Anarchia Anglicana (1649) refers to "new-erected sodoms and spintries at the Mulberry Garden at S. James's"; this suggests it may have been a place of debauchery. Eventually, in the late 17th century, the freehold was inherited from the property tycoon Sir Hugh Audley by the great heiress Mary Davies.

Question: Which property tycoon inherited the property in the late 17th century?


Answer: Eye Cross

Question: Which village had fallen into decay?


Answer: James I

Question: Who established a mulberry garden on the property?


Answer: silk

Question: What product did the mulberry garden produce?


Answer: Clement Walker

Question: Who suggests that the mulberry garden is likely a place for debauchery?


Answer: the freehold

Question: What about the palace was subject to speculation in the 17th century?


Answer: Eye Cross

Question: Which village had fallen into decay but the 17th century?


Answer: James I

Question: Who sold off part of the Crown Freehold?


Answer: mulberry

Question: What type of garden did James I create?


Answer: silk.

Question: What did the mulberry garden produce?


Answer: Sir William Blake

Context: Possibly the first house erected within the site was that of a Sir William Blake, around 1624. The next owner was Lord Goring, who from 1633 extended Blake's house and developed much of today's garden, then known as Goring Great Garden. He did not, however, obtain the freehold interest in the mulberry garden. Unbeknown to Goring, in 1640 the document "failed to pass the Great Seal before King Charles I fled London, which it needed to do for legal execution". It was this critical omission that helped the British royal family regain the freehold under King George III.

Question: Who built the first house on the site?


Answer: Lord Goring

Question: Which owner developed much of the garden still seen today?


Answer: Goring Great Garden

Question: What was Lord Goring's garden known as?


Answer: King George III

Question: Under which king did the Royal Family regain the freehold title of the property?


Answer: King Charles I

Question: Which king failed to execute Goring's freehold document before fleeing to London?


Answer: Sir William Blake

Question: Who owned the first house built on the site?


Answer: Lord Goring

Question: Who developed what is much of today's garden at Buckingham?


Answer: Goring Great Garden

Question: What was the name of Lord Goring Garden?


Answer: King Charles I

Question: Which king fled to London leaving allowing the Royal family to keep it's freehold on the property?


Answer: 1703

Context: The house which forms the architectural core of the palace was built for the first Duke of Buckingham and Normanby in 1703 to the design of William Winde. The style chosen was of a large, three-floored central block with two smaller flanking service wings. Buckingham House was eventually sold by Buckingham's descendant, Sir Charles Sheffield, in 1761 to George III for £21,000. Sheffield's leasehold on the mulberry garden site, the freehold of which was still owned by the royal family, was due to expire in 1774.

Question: In what year did William Winde design the house which forms the core of the palace?


Answer: Sir Charles Sheffield

Question: Who sold Buckingham house in 1761?


Answer: £21,000

Question: How much did George III pay for the house?


Answer: 1774

Question: In what year was the leasehold of the Mulberry site due to expire?


Answer: two

Question: How many flanking service wings did the original Buckingham House have?


Answer: Duke of Buckingham and Normanby

Question: The house which is the core of Buckingham was first built for who?


Answer: William Winde

Question: Who designed the house for the Duke of Buckingham?


Answer: two

Question: How many flanking service wings did Buckingham House have?


Answer: George III

Question: Who bought Buckingham House in 1761?


Answer: £21,000

Question: How much did George III pay for Buckingham House?


Answer: a small, comfortable home

Context: Remodelling of the structure began in 1762. After his accession to the throne in 1820, King George IV continued the renovation with the idea in mind of a small, comfortable home. While the work was in progress, in 1826, the King decided to modify the house into a palace with the help of his architect John Nash. Some furnishings were transferred from Carlton House, and others had been bought in France after the French Revolution. The external façade was designed keeping in mind the French neo-classical influence preferred by George IV. The cost of the renovations grew dramatically, and by 1829 the extravagance of Nash's designs resulted in his removal as architect. On the death of George IV in 1830, his younger brother King William IV hired Edward Blore to finish the work. At one stage, William considered converting the palace into the new Houses of Parliament, after the destruction of the Palace of Westminster by fire in 1834.

Question: What did King George IV originally want the structure to be?


Answer: new Houses of Parliament

Question: King William thought about converting the palace into what after a fire destroyed the Palace of Westminster in 1834?


Answer: John Nash

Question: Which architect helped modify the house into a palace?


Answer: 1829

Question: In what year was Nash removed as architect?


Answer: Edward Blore

Question: Who was hired in 1830 to finish the work on the palace?


Answer: 1762

Question: What year did remodeling of Buckingham House begin?


Answer: a small, comfortable home

Question: What was George IV's original plan for the house?


Answer: 1826

Question: What year did the king decide to make it into a palace?


Answer: John Nash

Question: Who was the main architect that transformed the house into the palace?


Answer: Edward Blore

Question: Who did King William IV hired to finish the work after Nash was fired?


Answer: Queen Victoria

Context: Buckingham Palace finally became the principal royal residence in 1837, on the accession of Queen Victoria, who was the first monarch to reside there; her predecessor William IV had died before its completion. While the state rooms were a riot of gilt and colour, the necessities of the new palace were somewhat less luxurious. For one thing, it was reported the chimneys smoked so much that the fires had to be allowed to die down, and consequently the court shivered in icy magnificence. Ventilation was so bad that the interior smelled, and when a decision was taken to install gas lamps, there was a serious worry about the build-up of gas on the lower floors. It was also said that staff were lax and lazy and the palace was dirty. Following the queen's marriage in 1840, her husband, Prince Albert, concerned himself with a reorganisation of the household offices and staff, and with the design faults of the palace. The problems were all rectified by the close of 1840. However, the builders were to return within the decade.

Question: Who was the first monarch to reside at Buckingham Palace?


Answer: William IV

Question: Who died before the palace was completed?


Answer: 1837

Question: Buckingham became a principle residence for the Royal Family in which year?


Answer: the chimneys smoked

Question: What was the problem with chimneys in the palace?


Answer: 1840

Question: At the end of which year were most of the design problems of the palace rectified under Prince Albert?


Answer: 1837

Question: When did Buckingham officially become the principle royal residence?


Answer: Queen Victoria

Question: Who was the first monarch to reside there?


Answer: William IV

Question: Who died before seeing Buckingham Palace's completion?


Answer: the chimneys smoked

Question: What was the problem with the palace's chimneys?


Answer: Prince Albert

Question: Who dealt with the design faults of the palace?


Answer: Edward Blore

Context: By 1847, the couple had found the palace too small for court life and their growing family, and consequently the new wing, designed by Edward Blore, was built by Thomas Cubitt, enclosing the central quadrangle. The large East Front, facing The Mall, is today the "public face" of Buckingham Palace, and contains the balcony from which the royal family acknowledge the crowds on momentous occasions and after the annual Trooping the Colour. The ballroom wing and a further suite of state rooms were also built in this period, designed by Nash's student Sir James Pennethorne.

Question: Who designed the new wing for the palace in 1847?


Answer: Thomas Cubitt

Question: The new wing was built by whom?


Answer: "public face" of Buckingham Palace

Question: What is the East front of the palace known as?


Answer: the balcony

Question: The East Front contains what famous feature?


Answer: Sir James Pennethorne.

Question: Who was the student of Nash that designed the ballroom wing?


Answer: Edward Blore

Question: Who designed a new wing for Queen Victoria and Prince Albert when they felt they needed more space?


Answer: Thomas Cubitt

Question: Who built the new wing?


Answer: The large East Front

Question: What is considered the public face of the palace?


Answer: The ballroom wing

Question: What other wing was built during this time?


Answer: Sir James Pennethorne

Question: Which of Nash's students designed The Ballroom?


Answer: musical entertainments

Context: Before Prince Albert's death, the palace was frequently the scene of musical entertainments, and the greatest contemporary musicians entertained at Buckingham Palace. The composer Felix Mendelssohn is known to have played there on three occasions. Johann Strauss II and his orchestra played there when in England. Strauss's "Alice Polka" was first performed at the palace in 1849 in honour of the queen's daughter, Princess Alice. Under Victoria, Buckingham Palace was frequently the scene of lavish costume balls, in addition to the usual royal ceremonies, investitures and presentations.

Question: The palace frequently hosted which type of events prior to the death of Prince Albert?


Answer: Felix Mendelssohn

Question: Which composer played at Buckingham on three occasions?


Answer: Alice Polka

Question: Which piece of music by Johann Strauss was first performed at Buckingham in honor of Princess Alice?


Answer: lavish costume balls

Question: Queen Victoria hosted which type of balls?


Answer: musical entertainments

Question: Before Prince Albert died what sort of entertainment was held at Buckingham?


Answer: Felix Mendelssohn

Question: Which composer played there on three occasions?


Answer: Johann Strauss II

Question: Who performed Alice Polka in honor of Princess Alice?


Answer: lavish costume balls

Question: What type of balls did Queen Victoria hold?


Answer: 1861

Context: Widowed in 1861, the grief-stricken Queen withdrew from public life and left Buckingham Palace to live at Windsor Castle, Balmoral Castle and Osborne House. For many years the palace was seldom used, even neglected. In 1864, a note was found pinned to the fence of Buckingham Palace, saying: "These commanding premises to be let or sold, in consequence of the late occupant's declining business." Eventually, public opinion forced the Queen to return to London, though even then she preferred to live elsewhere whenever possible. Court functions were still held at Windsor Castle, presided over by the sombre Queen habitually dressed in mourning black, while Buckingham Palace remained shuttered for most of the year.

Question: When year did Prince Albert die?


Answer: public opinion

Question: What forced the Queen to return to London?


Answer: the palace was seldom used, even neglected.

Question: What was the fate of Buckingham after the left?


Answer: Windsor Castle

Question: Where were court functions held upon the Queens return to London?


Answer: 1861

Question: When did Prince Albert die?


Answer: left Buckingham Palace

Question: What did Queen Victoria do in response to his death?


Answer: Osborne House

Question: Which house did Queen Victoria stay at after she left Buckingham?


Answer: palace was seldom used, even neglected

Question: What happened to Buckingham after Queen Victoria left?


Answer: Windsor Castle

Question: Where did Queen Victoria hold court functions during this time?


Answer: 52

Context: The palace measures 108 metres (354 ft) by 120 metres (390 ft), is 24 metres (79 ft) high and contains over 77,000 m2 (830,000 sq ft) of floorspace. The floor area is smaller than the Royal Palace of Madrid, the Papal Palace in Rome, the Louvre in Paris, the Hofburg Palace in Vienna, or the Forbidden City. There are 775 rooms, including 19 state rooms, 52 principal bedrooms, 188 staff bedrooms, 92 offices, and 78 bathrooms. The principal rooms are contained on the piano nobile behind the west-facing garden façade at the rear of the palace. The centre of this ornate suite of state rooms is the Music Room, its large bow the dominant feature of the façade. Flanking the Music Room are the Blue and the White Drawing Rooms. At the centre of the suite, serving as a corridor to link the state rooms, is the Picture Gallery, which is top-lit and 55 yards (50 m) long. The Gallery is hung with numerous works including some by Rembrandt, van Dyck, Rubens and Vermeer; other rooms leading from the Picture Gallery are the Throne Room and the Green Drawing Room. The Green Drawing Room serves as a huge anteroom to the Throne Room, and is part of the ceremonial route to the throne from the Guard Room at the top of the Grand Staircase. The Guard Room contains white marble statues of Queen Victoria and Prince Albert, in Roman costume, set in a tribune lined with tapestries. These very formal rooms are used only for ceremonial and official entertaining, but are open to the public every summer.

Question: How many principle bedrooms does the palace have?


Answer: 78

Question: How many bathrooms are there?


Answer: the Music Room

Question: A large bow is a large feature of the facade in which stateroom?


Answer: 55 yards

Question: How long is the Picture Gallery in yards?


Answer: The Guard Room

Question: Which rooms has large white marble statues of Prince Albert and Queen Victoria?


Answer: 77,000 m2 (830,000 sq ft)

Question: What is the floor space of the palace?


Answer: 19 state rooms

Question: How many staterooms does the palace have?


Answer: 78 bathrooms

Question: How many bathrooms does the palace have?


Answer: 92 offices

Question: How many offices does the palace have?


Answer: Emperor Napoleon III of France

Context: Directly underneath the State Apartments is a suite of slightly less grand rooms known as the semi-state apartments. Opening from the Marble Hall, these rooms are used for less formal entertaining, such as luncheon parties and private audiences. Some of the rooms are named and decorated for particular visitors, such as the 1844 Room, decorated in that year for the State visit of Tsar Nicholas I of Russia, and, on the other side of the Bow Room, the 1855 Room, in honour of the visit of Emperor Napoleon III of France. At the centre of this suite is the Bow Room, through which thousands of guests pass annually to the Queen's Garden Parties in the Gardens. The Queen and Prince Philip use a smaller suite of rooms in the north wing.

Question: The 1855 Room is name for which European emperor?


Answer: 1844 Room

Question: Which room is named for visit of Tsar Nicolas I of Russia?


Answer: Bow Room

Question: Guests attending the Queen's Garden Parties will mostly likely see which room?


Answer: the north wing

Question: Where are the suites located that the Queen and Prince Phillip use?


Answer: the semi-state apartments

Question: Which rooms are used for less formal entertaining such as luncheons or private audiences?


Answer: semi-state apartments

Question: What is the name of the slightly less luxurious staterooms located underneath the State Apartments?


Answer: less formal entertaining

Question: What type of entertaining are the semi-state apartments used for?


Answer: Tsar Nicholas I of Russia

Question: Who is the 1844 Room named after?


Answer: Emperor Napoleon III of France

Question: Who is the 1855 Room named after?


Answer: the north wing

Question: Where are the Queen and Prince Phillip's apartments located?


Answer: Brighton Pavilion

Context: Between 1847 and 1850, when Blore was building the new east wing, the Brighton Pavilion was once again plundered of its fittings. As a result, many of the rooms in the new wing have a distinctly oriental atmosphere. The red and blue Chinese Luncheon Room is made up from parts of the Brighton Banqueting and Music Rooms with a large oriental chimney piece sculpted by Richard Westmacott. The Yellow Drawing Room has wallpaper supplied in 1817 for the Brighton Saloon, and a chimney piece which is a European vision of how the Chinese chimney piece may appear. It has nodding mandarins in niches and fearsome winged dragons, designed by Robert Jones.

Question: Where did many of the fittings for the new east wing come from?


Answer: Between 1847 and 1850

Question: When was the new east wing built?


Answer: oriental

Question: What is the theme for the new east wing?


Answer: large oriental chimney piece

Question: The red and blue Chinese Luncheon Room has what as a main feature?


Answer: Robert Jones

Question: Who designed the chimney piece in The Yellow Drawing Room?


Answer: the new east wing

Question: What was Blore building between 1847 and 1850?


Answer: oriental

Question: Many rooms in the new east wing are in what style?


Answer: The red and blue Chinese Luncheon Room

Question: Parts of the Brighton Banqueting and Music Rooms from Brighton Pavilion make up which Buckingham Room?


Answer: Centre Room

Context: At the centre of this wing is the famous balcony with the Centre Room behind its glass doors. This is a Chinese-style saloon enhanced by Queen Mary, who, working with the designer Sir Charles Allom, created a more "binding" Chinese theme in the late 1920s, although the lacquer doors were brought from Brighton in 1873. Running the length of the piano nobile of the east wing is the great gallery, modestly known as the Principal Corridor, which runs the length of the eastern side of the quadrangle. It has mirrored doors, and mirrored cross walls reflecting porcelain pagodas and other oriental furniture from Brighton. The Chinese Luncheon Room and Yellow Drawing Room are situated at each end of this gallery, with the Centre Room obviously placed in the centre.

Question: Which room has the famous balcony used by the royals?


Answer: Chinese

Question: What is the main theme of the Centre Room?


Answer: Queen Mary

Question: Which Queen enhanced the Chinese theme of the Centre Room in the 1920s?


Answer: 1873

Question: The lacquer doors in the Centre Room were brought from Brighton in which year?


Answer: mirrored doors

Question: The Principle Corridor features which type of doors?


Answer: Centre Room

Question: Which room feature the famous balcony?


Answer: Sir Charles Allom

Question: Which designer did Queen Mary work with to enhance the Centre Room?


Answer: mirrored doors

Question: The Principle Corridor has which type of doors?


Answer: 1873

Question: What year were the lacquer doors brought from Brighton?


Answer: the Belgian Suite

Context: When paying a state visit to Britain, foreign heads of state are usually entertained by the Queen at Buckingham Palace. They are allocated a large suite of rooms known as the Belgian Suite, situated at the foot of the Minister's Staircase, on the ground floor of the north-facing Garden Wing. The rooms of the suite are linked by narrow corridors, one of them is given extra height and perspective by saucer domes designed by Nash in the style of Soane. A second corridor in the suite has Gothic influenced cross over vaulting. The Belgian Rooms themselves were decorated in their present style and named after Prince Albert's uncle Léopold I, first King of the Belgians. In 1936, the suite briefly became the private apartments of the palace when they were occupied by King Edward VIII.

Question: Where do foreign heads of stay usually stay in Buckingham Palace?


Answer: ground floor

Question: What floor are the Belgian Suites located?


Answer: the Minister's Staircase

Question: The Belgian Suite is located at the foot of which staircase?


Answer: by narrow corridors

Question: How are the rooms of the Belgian Suites linked?


Answer: the style of Soane

Question: What is the style of the saucer domes in the Belgian Suite?


Answer: the Belgian Suite

Question: Where do foreign heads of stay at Buckingham Palace?


Answer: Minister's Staircase

Question: The Belgian Suite is located at the bottom of which staircase?


Answer: the ground floor

Question: On which floor is the Belgian Suite located?


Answer: by narrow corridors

Question: How are the rooms in the Belgian Suite connected?


Answer: the style of Soane

Question: The saucer domes are in whose style?


Answer: art gallery

Context: Thus, Buckingham Palace is a symbol and home of the British monarchy, an art gallery and a tourist attraction. Behind the gilded railings and gates which were completed by the Bromsgrove Guild in 1911 and Webb's famous façade, which has been described in a book published by the Royal Collection as looking "like everybody's idea of a palace", is not only a weekday home of the Queen and Prince Philip but also the London residence of the Duke of York and the Earl and Countess of Wessex. The palace also houses the offices of the Queen, Prince Philip, Duke of York, Earl and Countess of Wessex, Princess Royal, and Princess Alexandra, and is the workplace of more than 800 people.

Question: Aside from being the home of the monarchy and a tourist attraction, what else is Buckingham Palace known for?


Answer: Bromsgrove Guild

Question: Who made the palaces gilded railings and gates?


Answer: more than 800

Question: How many people work at Buckingham Palace?


Answer: Duke of York

Question: Buckingham Palace is also the London Residence for which Duke?


Answer: the British monarchy

Question: Who is Buckingham palace home to?


Answer: Bromsgrove Guild

Question: Who completed the palaces gilded railing and gates?


Answer: 1911

Question: In what year were the railings and gates completed?


Answer: 800 people

Question: How many people work at Buckingham Palace?


Answer: Crown Estate

Context: The palace, like Windsor Castle, is owned by the Crown Estate. It is not the monarch's personal property, unlike Sandringham House and Balmoral Castle. Many of the contents from Buckingham Palace, Windsor Castle, Kensington Palace, and St James's Palace are part of the Royal Collection, held in trust by the Sovereign; they can, on occasion, be viewed by the public at the Queen's Gallery, near the Royal Mews. Unlike the palace and the castle, the purpose-built gallery is open continually and displays a changing selection of items from the collection. It occupies the site of the chapel destroyed by an air raid in World War II. The palace's state rooms have been open to the public during August and September and on selected dates throughout the year since 1993. The money raised in entry fees was originally put towards the rebuilding of Windsor Castle after the 1992 fire devastated many of its state rooms. 476,000 people visited the palace in the 2014–15 financial year.

Question: Buckingham Palace is actually owned by whom?


Answer: Queen's Gallery

Question: Where can the public view items from the Royal Collection?


Answer: chapel

Question: What was located on the site that is now the Queen's Gallery?


Answer: The palace's state rooms

Question: What part of the palace has been open to the public every August and September and other select dates since 1993?


Answer: Crown Estate

Question: Who owns Buckingham Palace and Windsor Castle?


Answer: at the Queen's Gallery

Question: Where can the public view the Royal Collection?


Answer: since 1993

Question: Since when have the palaces rooms been opened to the public?


Answer: 476,000 people

Question: How many people visited the palace in the 2014.2015 fiscal year?


Answer: there is no official dress code

Context: Formerly, men not wearing military uniform wore knee breeches of an 18th-century design. Women's evening dress included obligatory trains and tiaras or feathers in their hair (or both). The dress code governing formal court uniform and dress has progressively relaxed. After World War I, when Queen Mary wished to follow fashion by raising her skirts a few inches from the ground, she requested a lady-in-waiting to shorten her own skirt first to gauge the king's reaction. King George V was horrified, so the queen kept her hemline unfashionably low. Following their accession in 1936, King George VI and his consort, Queen Elizabeth, allowed the hemline of daytime skirts to rise. Today, there is no official dress code. Most men invited to Buckingham Palace in the daytime choose to wear service uniform or lounge suits; a minority wear morning coats, and in the evening, depending on the formality of the occasion, black tie or white tie.

Question: What is the official dress code today at Buckingham Palace?


Answer: Queen Mary

Question: Which Queen tried and failed to raise the hemline of her dress after WWI?


Answer: King George V

Question: Which King was horrified to see the Queen's hemline raised a few inches?


Answer: 1936

Question: The hemline of daytime skirts were allowed to rise after which year?


Answer: 18th-century design

Question: The knee breeches men formerly wore to the palace were of what era's design?


Answer: 18th-century design

Question: From what century were men's knee breeches worn at Buckingham designed in?


Answer: tiaras or feathers

Question: What were women obliged to wear in their hair?


Answer: Queen Mary

Question: Which queen wanted to shorten her skirt's hemline?


Answer: George V

Question: Which King was horrified to see the raised hemline on the Queen?


Answer: there is no official dress code

Question: What is the dress code today at Buckingham?


Answer: Edward VII

Context: Court presentations of aristocratic young ladies to the monarch took place at the palace from the reign of Edward VII. These young women were known as débutantes, and the occasion—termed their "coming out"—represented their first entrée into society. Débutantes wore full court dress, with three tall ostrich feathers in their hair. They entered, curtsied, and performed a choreographed backwards walk and a further curtsy, while manoeuvring a dress train of prescribed length. (The ceremony, known as an evening court, corresponded to the "court drawing rooms" of Victoria's reign.) After World War II, the ceremony was replaced by less formal afternoon receptions, usually without choreographed curtsies and court dress.

Question: Under whose reign did court presentations of young aristocratic ladies take place?


Answer: coming out

Question: What was the name for the ceremony where debutantes had their first introduction into society?


Answer: ostrich feathers

Question: Debutantes wore the feather of which bird in their hair?


Answer: less formal afternoon receptions

Question: After WWII "coming out" ceremonies were replaces with what event?


Answer: Edward VII

Question: Under whose reign were young debutantes presented to society at Court?


Answer: ostrich feathers

Question: What types of feathers did debutantes wear in their hair?


Answer: "coming out"

Question: What was the occasion where debutantes were presented to society called?


Answer: less formal afternoon receptions

Question: After WWII what was the coming out ceremony replaced with?


Answer: in the palace's Ballroom

Context: Investitures, which include the conferring of knighthoods by dubbing with a sword, and other awards take place in the palace's Ballroom, built in 1854. At 36.6 m (120 ft) long, 18 m (59 ft) wide and 13.5 m (44 ft) high, it is the largest room in the palace. It has replaced the throne room in importance and use. During investitures, the Queen stands on the throne dais beneath a giant, domed velvet canopy, known as a shamiana or a baldachin, that was used at the Delhi Durbar in 1911. A military band plays in the musicians' gallery as award recipients approach the Queen and receive their honours, watched by their families and friends.

Question: Where do Investitures take place?


Answer: 1854

Question: What year was The Ballroom built?


Answer: the throne room

Question: Which room has The Ballroom replaced in terms of both use and importance?


Answer: the palace's Ballroom

Question: What is the largest room in the palace?


Answer: the throne dais

Question: What does the Queen stand on during Investitures?


Answer: a sword

Question: Knighthood is given by being dubbed with what object?


Answer: Ballroom

Question: What is the largest room in the palace?


Answer: the throne room

Question: The Ballroom replaced which other room in terms of importance and use?


Answer: the Ballroom

Context: State banquets also take place in the Ballroom; these formal dinners are held on the first evening of a state visit by a foreign head of state. On these occasions, for up to 170 guests in formal "white tie and decorations", including tiaras, the dining table is laid with the Grand Service, a collection of silver-gilt plate made in 1811 for the Prince of Wales, later George IV. The largest and most formal reception at Buckingham Palace takes place every November when the Queen entertains members of the diplomatic corps. On this grand occasion, all the state rooms are in use, as the royal family proceed through them, beginning at the great north doors of the Picture Gallery. As Nash had envisaged, all the large, double-mirrored doors stand open, reflecting the numerous crystal chandeliers and sconces, creating a deliberate optical illusion of space and light.

Question: Where do State Banquets take place?


Answer: November

Question: In what month does the Queen entertain the diplomatic corps?


Answer: the Grand Service

Question: What is used to set the dining table for formal dinners?


Answer: 1811

Question: When was the Grand Service made?


Answer: the Prince of Wales

Question: For whom was the Grand Service made?


Answer: in the Ballroom

Question: Where do state banquets take place?


Answer: the first evening of a state visit by a foreign head of state

Question: When are state banquets held?


Answer: the Grand Service

Question: What is the dining table laid with for state banquets?


Answer: Prince of Wales

Question: Who was the Grand Service originally made for?


Answer: Nash

Context: Adjacent to the palace is the Royal Mews, also designed by Nash, where the royal carriages, including the Gold State Coach, are housed. This rococo gilt coach, designed by Sir William Chambers in 1760, has painted panels by G. B. Cipriani. It was first used for the State Opening of Parliament by George III in 1762 and has been used by the monarch for every coronation since George IV. It was last used for the Golden Jubilee of Elizabeth II. Also housed in the mews are the coach horses used at royal ceremonial processions.

Question: Who designed the Royal Mews?


Answer: the Royal Mews

Question: Where is the Gold State Coach housed?


Answer: Sir William Chambers

Question: Who designed the Gold State Coach?


Answer: 1762

Question: When was the Gold State Coach first used?


Answer: horses

Question: The Royal Mews houses which type of animal?


Answer: Nash

Question: Who designed the Royal Mews?


Answer: the Royal Mews

Question: Where is the Gold State Coach kept?


Answer: Sir William Chambers

Question: Who designed the Gold State Coach?


Answer: 1762

Question: In what year was the Gold State Coach first used?


Answer: horses

Question: What animals are kept in the mews?


Answer: 1901

Context: In 1901 the accession of Edward VII saw new life breathed into the palace. The new King and his wife Queen Alexandra had always been at the forefront of London high society, and their friends, known as "the Marlborough House Set", were considered to be the most eminent and fashionable of the age. Buckingham Palace—the Ballroom, Grand Entrance, Marble Hall, Grand Staircase, vestibules and galleries redecorated in the Belle époque cream and gold colour scheme they retain today—once again became a setting for entertaining on a majestic scale but leaving some to feel King Edward's heavy redecorations were at odds with Nash's original work.

Question: In what year did Edward VII ascend to the throne?


Answer: "the Marlborough House Set"

Question: Kind Edward VII and Queen Alexandra's friends were know as what?


Answer: Nash's

Question: Some thought that King Edward VII's redecoration choices were at odds with whose prior work?


Answer: King Edward

Question: Which king commissioned massive redecoration in the Belle Epoque cream and gold color scheme?


Answer: the Marlborough House Set

Question: What were the group of friends of King Edward VII and Queen Alexandra called?


Answer: King Edward's heavy redecorations

Question: What was at odds with Nash's original work in the palace?


Answer: 1901

Question: When did King Edward VII take the throne?


Answer: Belle époque cream and gold

Question: What colors were used in the redecorations overseen by King Edward VII?


Answer: King George V

Context: The last major building work took place during the reign of King George V when, in 1913, Sir Aston Webb redesigned Blore's 1850 East Front to resemble in part Giacomo Leoni's Lyme Park in Cheshire. This new, refaced principal façade (of Portland stone) was designed to be the backdrop to the Victoria Memorial, a large memorial statue of Queen Victoria, placed outside the main gates. George V, who had succeeded Edward VII in 1910, had a more serious personality than his father; greater emphasis was now placed on official entertaining and royal duties than on lavish parties. He arranged a series of command performances featuring jazz musicians such as the Original Dixieland Jazz Band (1919) – the first jazz performance for a head of state, Sidney Bechet, and Louis Armstrong (1932), which earned the palace a nomination in 2009 for a (Kind of) Blue Plaque by the Brecon Jazz Festival as one of the venues making the greatest contribution to jazz music in the United Kingdom. George V's wife Queen Mary was a connoisseur of the arts, and took a keen interest in the Royal Collection of furniture and art, both restoring and adding to it. Queen Mary also had many new fixtures and fittings installed, such as the pair of marble Empire-style chimneypieces by Benjamin Vulliamy, dating from 1810, which the Queen had installed in the ground floor Bow Room, the huge low room at the centre of the garden façade. Queen Mary was also responsible for the decoration of the Blue Drawing Room. This room, 69 feet (21 metres) long, previously known as the South Drawing Room, has a ceiling designed specially by Nash, coffered with huge gilt console brackets.

Question: Under whose reign did the last major building works take place?


Answer: Portland stone

Question: The principle facade of the East Front is made from what type of stone?


Answer: George V

Question: Which king preferred official entertaining and royal duties to lavish parties?


Answer: Queen Mary

Question: Who added and restored furniture to The Royal Collection?


Answer: Queen Mary

Question: Who was responsible for decorating The Blue Drawing Room?


Answer: Sir Aston Webb

Question: Who redesigned Blore's 1850 East Front?


Answer: Portland stone

Question: The refaced facade was made from what type of stone?


Answer: George V

Question: Which king placed more emphasis on official entertaining and royal duties instead of lavish parties?


Answer: Royal Collection of furniture and art

Question: What collection did Queen Mary take an interest in by adding and restoring pieces?


Answer: Queen Mary

Question: Who decorated the Blue Drawing Room?


Answer: King George V and Queen Mary

Context: During World War I, the palace, then the home of King George V and Queen Mary, escaped unscathed. Its more valuable contents were evacuated to Windsor but the royal family remained in situ. The King imposed rationing at the palace, much to the dismay of his guests and household. To the King's later regret, David Lloyd George persuaded him to go further by ostentatiously locking the wine cellars and refraining from alcohol, to set a good example to the supposedly inebriated working class. The workers continued to imbibe and the King was left unhappy at his enforced abstinence. In 1938, the north-west pavilion, designed by Nash as a conservatory, was converted into a swimming pool.

Question: Who lived at Buckingham Palace during WWI?


Answer: Windsor

Question: Where were valuable items from Buckingham Palace taken during WWI?


Answer: alcohol

Question: The king refrained from doing what during the war?


Answer: 1938

Question: In what year was the north-west pavilion turned into a swimming pool?


Answer: David Lloyd George

Question: Who persuaded the king to lock the wine cellars during WWI?


Answer: World War I

Question: Buckingham Palace was untouched during which war?


Answer: Windsor

Question: Where were valuables evacuated to during the war?


Answer: alcohol

Question: What did the King give up during the war?


Answer: David Lloyd George

Question: Who convinced the king to lock the wine cellars?


Answer: swimming pool

Question: What was the north-west pavilion converted into in 1938?


Answer: nine times

Context: During World War II, the palace was bombed nine times, the most serious and publicised of which resulted in the destruction of the palace chapel in 1940. Coverage of this event was played in cinemas all over the UK to show the common suffering of rich and poor. One bomb fell in the palace quadrangle while King George VI and Queen Elizabeth were in residence, and many windows were blown in and the chapel destroyed. War-time coverage of such incidents was severely restricted, however. The King and Queen were filmed inspecting their bombed home, the smiling Queen, as always, immaculately dressed in a hat and matching coat seemingly unbothered by the damage around her. It was at this time the Queen famously declared: "I'm glad we have been bombed. Now I can look the East End in the face". The royal family were seen as sharing their subjects' hardship, as The Sunday Graphic reported:

Question: How many times was the palace bombed in WWII?


Answer: the palace chapel

Question: What was destroyed in 1940?


Answer: King George VI and Queen Elizabeth

Question: Which monarchs were in residence at Buckingham Palace during WWII?


Answer: the common suffering of rich and poor

Question: The bombing of Buckingham Palace showed what to the public?


Answer: the chapel

Question: What was destroyed in one of the bombing that hit the palace in WWII?


Answer: inspecting their bombed home

Question: The King and Queen were filmed doing what after a bombing?


Answer: their subjects' hardship

Question: The royal family was seen as sharing what with their subjects after the bombings?


Answer: 15 September 1940

Context: On 15 September 1940, known as the Battle of Britain Day, an RAF pilot, Ray Holmes of No. 504 Squadron RAF rammed a German bomber he believed was going to bomb the Palace. Holmes had run out of ammunition and made the quick decision to ram it. Holmes bailed out. Both aircraft crashed. In fact the Dornier Do 17 bomber was empty. It had already been damaged, two of its crew had been killed and the remainder bailed out. Its pilot, Feldwebel Robert Zehbe, landed, only to die later of wounds suffered during the attack. During the Dornier's descent, it somehow unloaded its bombs, one of which hit the Palace. It then crashed into the forecourt of London Victoria station. The bomber's engine was later exhibited at the Imperial War Museum in London. The British pilot became a King's Messenger after the war, and died at the age of 90 in 2005.

Question: What is the date of the Battle of Britain Day?


Answer: the Palace

Question: What did Ray Holmes think the German pilot was going to bomb?


Answer: Dornier Do 17 bomber

Question: What type of airplane was the German craft Holmes rammed into?


Answer: King's Messenger

Question: After the war what did Holmes become?


Answer: 2005

Question: What year did Ray Holmes die?


Answer: the Battle of Britain Day

Question: What is September 15, 1940 known as?


Answer: the Palace

Question: What did Ray Holmes believe the German pilot was targeting?


Answer: ram it

Question: What did Holmes do to stop the German Plane?


Answer: Dornier Do 17 bomber

Question: What type of aircraft was the German Plane?


Answer: 2005

Question: When did Holmes die?


Answer: electric current

Context: An incandescent light bulb, incandescent lamp or incandescent light globe is an electric light with a wire filament heated to a high temperature, by passing an electric current through it, until it glows with visible light (incandescence). The hot filament is protected from oxidation with a glass or quartz bulb that is filled with inert gas or evacuated. In a halogen lamp, filament evaporation is prevented by a chemical process that redeposits metal vapor onto the filament, extending its life. The light bulb is supplied with electric current by feed-through terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.

Question: What type of energy makes an incandescent light bulb glow?


Answer: wire filament

Question: Which part of the incandescent light bulb is heated?


Answer: feed-through terminals or wires embedded in the glass

Question: What part of a halogen light bulb supplies electric current?


Answer: a socket

Question: What provides the electricity to most light bulbs?


Answer: incandescent light bulb

Question: Which type of light bulb uses inert gas?


Answer: less efficient

Context: Incandescent bulbs are much less efficient than most other types of electric lighting; incandescent bulbs convert less than 5% of the energy they use into visible light, with standard light bulbs averaging about 2.2%. The remaining energy is converted into heat. The luminous efficacy of a typical incandescent bulb is 16 lumens per watt, compared with 60 lm/W for a compact fluorescent bulb or 150 lm/W for some white LED lamps. Some applications of the incandescent bulb deliberately use the heat generated by the filament. Such applications include incubators, brooding boxes for poultry, heat lights for reptile tanks, infrared heating for industrial heating and drying processes, lava lamps, and the Easy-Bake Oven toy. Incandescent bulbs typically have short lifetimes compared with other types of lighting; around 1,000 hours for home light bulbs versus typically 10,000 hours for compact fluorescents and 30,000 hours for lighting LEDs.

Question: Are incandescent bulbs more or less efficient than most electric lighting?


Answer: 2.2%

Question: What percentage of energy does a standard light bulb actually convert to visible light?


Answer: LED

Question: Which is more efficient: compact fluorescent or LED lights?


Answer: 1,000 hours

Question: How long does a typical incandescent light bulb last?


Answer: The remaining energy is converted into heat.

Question: What happens to the energy that an incandescent bulb does not convert into light?


Answer: prohibited them already

Context: Incandescent bulbs have been replaced in many applications by other types of electric light, such as fluorescent lamps, compact fluorescent lamps (CFL), cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, and light-emitting diode lamps (LED). Some jurisdictions, such as the European Union, China, Canada and United States, are in the process of phasing out the use of incandescent light bulbs while others, including Colombia, Mexico, Cuba, Argentina, Brazil and Australia, have prohibited them already.

Question: What law did Australia make about incandescent light bulbs?


Answer: phasing out the use of incandescent light bulbs

Question: How is the United States treating incandescent light bulbs?


Answer: cold cathode fluorescent lamps

Question: What does the acronym CCFL refer to?


Answer: compact fluorescent lamps

Question: What does the acronym CFL refer to?


Answer: light-emitting diode

Question: What does the acronym LED refer to?


Answer: Alexander Lodygin

Context: In 1872, Russian Alexander Lodygin invented an incandescent light bulb and obtained a Russian patent in 1874. He used as a burner two carbon rods of diminished section in a glass receiver, hermetically sealed, and filled with nitrogen, electrically arranged so that the current could be passed to the second carbon when the first had been consumed. Later he lived in the USA, changed his name to Alexander de Lodyguine and applied and obtained patents for incandescent lamps having chromium, iridium, rhodium, ruthenium, osmium, molybdenum and tungsten filaments, and a bulb using a molybdenum filament was demonstrated at the world fair of 1900 in Paris.

Question: Who patented an incandescent light bulb in Russia in 1874?


Answer: two carbon rods

Question: What did Lodygin use as a burner in his lamp?


Answer: 1900

Question: In what year did Lodygin demonstrate a lamp at the World's Fair?


Answer: Alexander de Lodyguine

Question: What did Lodygin change his name to after moving to the USA?


Answer: 1872

Question: When did Lodygin invent his first lamp?


Answer: at a meeting of the Newcastle Chemical Society

Context: With the help of Charles Stearn, an expert on vacuum pumps, in 1878, Swan developed a method of processing that avoided the early bulb blackening. This received a British Patent in 1880.[dubious – discuss] On 18 December 1878, a lamp using a slender carbon rod was shown at a meeting of the Newcastle Chemical Society, and Swan gave a working demonstration at their meeting on 17 January 1879. It was also shown to 700 who attended a meeting of the Literary and Philosophical Society of Newcastle upon Tyne on 3 February 1879. These lamps used a carbon rod from an arc lamp rather than a slender filament. Thus they had low resistance and required very large conductors to supply the necessary current, so they were not commercially practical, although they did furnish a demonstration of the possibilities of incandescent lighting with relatively high vacuum, a carbon conductor, and platinum lead-in wires. Besides requiring too much current for a central station electric system to be practical, they had a very short lifetime. Swan turned his attention to producing a better carbon filament and the means of attaching its ends. He devised a method of treating cotton to produce 'parchmentised thread' and obtained British Patent 4933 in 1880. From this year he began installing light bulbs in homes and landmarks in England. His house was the first in the world to be lit by a lightbulb and also the first house in the world to be lit by hydroelectric power. In 1878 the home of Lord Armstrong at Cragside was also among the first houses to be lit by electricity. In the early 1880s he had started his company. In 1881, the Savoy Theatre in the City of Westminster, London was lit by Swan incandescent lightbulbs, which was the first theatre, and the first public building in the world, to be lit entirely by electricity.

Question: Where did Joseph Swan demonstrate his lamp in January 1879?


Answer: Charles Stearn

Question: Which vacuum pump expert helped Swan invent his lamp?


Answer: 'parchmentised thread'

Question: Why was Swan's first lamp not commercially viable?


Answer: 1880

Question: When did Swan receive a patent for parchmentised thread?


Answer: the Savoy Theatre in the City of Westminster, London

Question: What was the first public building to install electric lighting?


Answer: 1878

Context: Thomas Edison began serious research into developing a practical incandescent lamp in 1878. Edison filed his first patent application for "Improvement In Electric Lights" on 14 October 1878. After many experiments, first with carbon in the early 1880s and then with platinum and other metals, in the end Edison returned to a carbon filament. The first successful test was on 22 October 1879, and lasted 13.5 hours. Edison continued to improve this design and by 4 November 1879, filed for a US patent for an electric lamp using "a carbon filament or strip coiled and connected ... to platina contact wires." Although the patent described several ways of creating the carbon filament including using "cotton and linen thread, wood splints, papers coiled in various ways," Edison and his team later discovered that a carbonized bamboo filament could last more than 1200 hours. In 1880, the Oregon Railroad and Navigation Company steamer, Columbia, became the first application for Edison's incandescent electric lamps (it was also the first ship to execute use of a dynamo).

Question: When did Edison begin research into incandescent lighting?


Answer: carbon

Question: With what material did Edison make his first filament?


Answer: 13.5 hours

Question: How long did Edison's light burn during his first successful test in 1879?


Answer: bamboo

Question: What type of wood did Edison use in his improved filament?


Answer: Columbia

Question: What was the name of the first ship to use Edison's lamp?


Answer: Albon Man

Context: Albon Man, a New York lawyer, started Electro-Dynamic Light Company in 1878 to exploit his patents and those of William Sawyer. Weeks later the United States Electric Lighting Company was organized. This company didn't made their first commercial installation of incandescent lamps until the fall of 1880 at the Mercantile Safe Deposit Company in New York City, about six months after the Edison incandescent lamps had been installed on the Columbia. Hiram S. Maxim was the chief engineer at the United States Electric Lighting Company.

Question: Who founded Electro-Dynamic Light Company?


Answer: Hiram S. Maxim

Question: Who was the chief engineer at the United States Electric Lighting Company?


Answer: Mercantile Safe Deposit Company

Question: Where did Electro-Dynamic Light Company install its first lights?


Answer: fall of 1880

Question: When did Electro-Dynamic Light Company install its first lights?


Answer: Electro-Dynamic Light Company

Question: Which company was organized first, Electro-Dynamic Light Company or United States Electric Lighting Company?


Answer: Lewis Latimer

Context: Lewis Latimer, employed at the time by Edison, developed an improved method of heat-treating carbon filaments which reduced breakage and allowed them to be molded into novel shapes, such as the characteristic "M" shape of Maxim filaments. On 17 January 1882, Latimer received a patent for the "Process of Manufacturing Carbons", an improved method for the production of light bulb filaments, which was purchased by the United States Electric Light Company. Latimer patented other improvements such as a better way of attaching filaments to their wire supports.

Question: Who developed a heat-treating method that allowed carbon filaments to be molded into shapes?


Answer: 17 January 1882

Question: When did Latimer patent his "Process of Manufacturing Carbons"?


Answer: United States Electric Light Company

Question: Which company purchased Latimer's patent?


Answer: Edison

Question: Who employed Latimer when he developed his first patent?


Answer: Hungarian Sándor Just and Croatian Franjo Hanaman

Context: On 13 December 1904, Hungarian Sándor Just and Croatian Franjo Hanaman were granted a Hungarian patent (No. 34541) for a tungsten filament lamp that lasted longer and gave brighter light than the carbon filament. Tungsten filament lamps were first marketed by the Hungarian company Tungsram in 1904. This type is often called Tungsram-bulbs in many European countries. Filling a bulb with an inert gas such as argon or nitrogen retards the evaporation of the tungsten filament compared to operating it in a vacuum. This allows for greater temperatures and therefore greater efficacy with less reduction in filament life.

Question: Which inventors patented the tungsten filament lamp?


Answer: 13 December 1904

Question: When did Just and Hanaman receive their patent for the tungsten filament lamp?


Answer: Tungsram

Question: Which company first marketed the tungsten filament lamp?


Answer: argon or nitrogen

Question: What type of gas fills a tungsten filament bulb?


Answer: Tungsram-bulbs

Question: What is a common alternate name for the tungsten filament bulb in Europe?


Answer: radiant luminous efficacy

Context: Luminous efficacy of a light source may be defined in two ways. The radiant luminous efficacy (LER) is the ratio of the visible light flux emitted (the luminous flux) to the total power radiated over all wavelengths. The source luminous efficacy (LES) is the ratio of the visible light flux emitted (the luminous flux) to the total power input to the source, such as a lamp. Visible light is measured in lumens, a unit which is defined in part by the differing sensitivity of the human eye to different wavelengths of light. Not all wavelengths of visible electromagnetic energy are equally effective at stimulating the human eye; the luminous efficacy of radiant energy (LER) is a measure of how well the distribution of energy matches the perception of the eye. The units of luminous efficacy are "lumens per watt" (lpw). The maximum LER possible is 683 lm/W for monochromatic green light at 555 nanometers wavelength, the peak sensitivity of the human eye.

Question: What does the acronym LER refer to?


Answer: 683 lm/W

Question: What is the maximum LER possible?


Answer: two ways

Question: In how many ways can one define luminous efficacy of a light source?


Answer: the ratio of the visible light flux emitted (the luminous flux) to the total power radiated over all wavelengths

Question: What is the definition of radiant luminous efficacy?


Answer: source luminous efficacy

Question: What does the acronym LES refer to?


Answer: 6,300 °C

Context: The spectrum emitted by a blackbody radiator at temperatures of incandescent bulbs does not match the sensitivity characteristics of the human eye; the light emitted does not appear white, and most is not in the range of wavelengths at which the eye is most sensitive. Tungsten filaments radiate mostly infrared radiation at temperatures where they remain solid – below 3,695 K (3,422 °C; 6,191 °F). Donald L. Klipstein explains it this way: "An ideal thermal radiator produces visible light most efficiently at temperatures around 6,300 °C (6,600 K; 11,400 °F). Even at this high temperature, a lot of the radiation is either infrared or ultraviolet, and the theoretical luminous efficacy (LER) is 95 lumens per watt." No known material can be used as a filament at this ideal temperature, which is hotter than the sun's surface. An upper limit for incandescent lamp luminous efficacy (LER) is around 52 lumens per watt, the theoretical value emitted by tungsten at its melting point.

Question: At what temperature does a thermal radiator most efficiently produce light?


Answer: 52 lumens per watt

Question: What is the upper limit for LER of an incandescent lamp?


Answer: infrared radiation

Question: What type of radiation makes up the majority of tungsten filament emissions?


Answer: the light emitted does not appear white,

Question: What is the flaw in the color of light produced by an incandescent bulb?


Answer: 52 lumens per watt

Question: What is the theoretical LER value of tungsten at its melting point?


Answer: to avoid too "warm" or "cool" colors

Context: Although inefficient, incandescent light bulbs have an advantage in applications where accurate color reproduction is important, since the continuous blackbody spectrum emitted from an incandescent light-bulb filament yields near-perfect color rendition, with a color rendering index of 100 (the best possible). White-balancing is still required to avoid too "warm" or "cool" colors, but this is a simple process that requires only the color temperature in Kelvin as input for modern, digital visual reproduction equipment such as video or still cameras unless it is completely automated. The color-rendering performance of incandescent lights cannot be matched by LEDs or fluorescent lights, although they can offer satisfactory performance for non-critical applications such as home lighting. White-balancing such lights is therefore more complicated, requiring additional adjustments to reduce for example green-magenta color casts, and even when properly white-balanced, the color reproduction will not be perfect.

Question: What is the purpose of white-balancing?


Answer: incandescent lights

Question: Of incandescent lights, fluorescent lights and LEDs, which has the best color-rendering performance?


Answer: 100

Question: What is the color rendering index of an incandescent light?


Answer: the continuous blackbody spectrum emitted from an incandescent light-bulb filament

Question: Why do incandescent lights have superior color rendering?


Answer: 100

Question: What is the highest possible color rendering index score?


Answer: higher

Context: There are many non-incandescent light sources, such as the fluorescent lamp, high-intensity discharge lamps and LED lamps, which have higher luminous efficiency, and some have been designed to be retrofitted in fixtures for incandescent lights. These devices produce light by luminescence. These lamps produce discrete spectral lines and do not have the broad "tail" of invisible infrared emissions. By careful selection of which electron energy level transitions are used, and fluorescent coatings which modify the spectral distribution, the spectrum emitted can be tuned to mimic the appearance of incandescent sources, or other different color temperatures of white light. Due to the discrete spectral lines rather than a continuous spectrum, the light is not ideal for applications such as photography and cinematography.

Question: Do fluorescent lights have a higher or lower luminous efficiency than incandescents?


Answer: By careful selection of which electron energy level transitions are used, and fluorescent coatings which modify the spectral distribution

Question: How can luminescent light sources be modified to resemble the appearance of incandescents?


Answer: Due to the discrete spectral lines rather than a continuous spectrum

Question: Why are luminescent light sources not ideal for photography?


Answer: a building's air conditioning system

Context: The initial cost of an incandescent bulb is small compared to the cost of the energy it uses over its lifetime. Incandescent bulbs have a shorter life than most other lighting, an important factor if replacement is inconvenient or expensive. Some types of lamp, including incandescent and fluorescent, emit less light as they age; this may be an inconvenience, or may reduce effective lifetime due to lamp replacement before total failure. A comparison of incandescent lamp operating cost with other light sources must include illumination requirements, cost of the lamp and labor cost to replace lamps (taking into account effective lamp lifetime), cost of electricity used, effect of lamp operation on heating and air conditioning systems. When used for lighting in houses and commercial buildings, the energy lost to heat can significantly increase the energy required by a building's air conditioning system. During the heating season heat produced by the bulbs is not wasted, although in most cases it is more cost effective to obtain heat from the heating system. Regardless, over the course of a year a more efficient lighting system saves energy in nearly all climates.

Question: What appliance requires more energy due to the use of incandescent lighting?


Answer: shorter

Question: Do incandescent lights have a longer or shorter life than other lighting sources?


Answer: illumination requirements, cost of the lamp and labor cost to replace lamps (taking into account effective lamp lifetime), cost of electricity used

Question: What are some factors to consider in calculating operating costs of lighting?


Answer: less

Question: Do incandescent lights emit more, less, or the same amount of light as they age?


Answer: heat from the heating system

Question: What is more cost-effective, heat from incandescent bulbs or heat from a building's heating system?


Answer: more

Context: Since incandescent light bulbs use more energy than alternatives such as CFLs and LED lamps, many governments have introduced measures to ban their use, by setting minimum efficacy standards higher than can be achieved by incandescent lamps. Measures to ban light bulbs have been implemented in the European Union, the United States, Russia, Brazil, Argentina, Canada and Australia, among others. In the Europe the EC has calculated that the ban contributes 5 to 10 billion euros to the economy and saves 40 TWh of electricity every year, translating in CO2 emission reductions of 15 million tonnes.

Question: Do incandescent light bulbs use more or less energy as compared to CFLs and LED lamps?


Answer: 5 to 10 billion euros

Question: How much does the incandescent light ban in Europe contribute to the economy each year?


Answer: 40 TWh of electricity

Question: How much energy does the incandescent light ban in Europe save each year?


Answer: 15 million tonnes

Question: How much CO2 emissions does the incandescent light ban in Europe save each year?


Answer: by setting minimum efficacy standards higher than can be achieved by incandescent lamps

Question: How are laws written that bring about a ban of incandescent light bulbs?


Answer: better

Context: Objections to banning the use of incandescent light bulbs include the higher initial cost of alternatives and lower quality of light of fluorescent lamps. Some people have concerns about the health effects of fluorescent lamps. However, even though they contain mercury, the environmental performance of CFLs is much better than that of light bulbs, mostly because they consume much less energy and therefore strongly reduce the environmental impact of power production. LED lamps are even more efficient, and are free of mercury. They are regarded as the best solution in terms of cost effectiveness and robustness.

Question: Is the environmental performance of CFLs better or worse than that of incandescents?


Answer: LED lamps

Question: Which type of light bulbs is considered most cost effective and robust?


Answer: higher initial cost of alternatives and lower quality of light of fluorescent lamps

Question: What are some objections to banning incandescent bulbs?


Answer: mercury

Question: What substance in CFL bulbs raises health concerns?


Answer: much less

Question: Do CFLs consume more, less, or the same amount of energy as incandescent bulbs?


Answer: Philips

Context: Prompted by legislation in various countries mandating increased bulb efficiency, new "hybrid" incandescent bulbs have been introduced by Philips. The "Halogena Energy Saver" incandescents can produce about 23 lm/W; about 30 percent more efficient than traditional incandescents, by using a reflective capsule to reflect formerly wasted infrared radiation back to the filament from which it can be re-emitted as visible light. This concept was pioneered by Duro-Test in 1980 with a commercial product that produced 29.8 lm/W. More advanced reflectors based on interference filters or photonic crystals can theoretically result in higher efficiency, up to a limit of about 270 lm/W (40% of the maximum efficacy possible). Laboratory proof-of-concept experiments have produced as much as 45 lm/W, approaching the efficacy of compact fluorescent bulbs.

Question: Which company introduced hybrid incandescent bulbs?


Answer: 30 percent

Question: How much more efficient are Halogena Energy Saver bulbs compared to incandescents?


Answer: Duro-Test

Question: What company first marketed light bulbs using the reflective capsule technique to increase energy efficiency?


Answer: 270 lm/W

Question: What is the theoretical maximum efficiency of reflective capsule bulbs?


Answer: 45 lm/W

Question: What is the maximum efficiency of reflective capsule bulbs as tested in labs?


Answer: the envelope

Context: Incandescent light bulbs consist of an air-tight glass enclosure (the envelope, or bulb) with a filament of tungsten wire inside the bulb, through which an electric current is passed. Contact wires and a base with two (or more) conductors provide electrical connections to the filament. Incandescent light bulbs usually contain a stem or glass mount anchored to the bulb's base that allows the electrical contacts to run through the envelope without air or gas leaks. Small wires embedded in the stem in turn support the filament and its lead wires.

Question: What is the name of the air-tight glass enclosure in an incandescent bulb?


Answer: tungsten wire

Question: What is the filament made of?


Answer: two (or more)

Question: How many conductors are present in the bulb's base?


Answer: a stem or glass mount anchored to the bulb's base

Question: What prevents air or gas leaks from a light bulb?


Answer: Small wires embedded in the stem in turn support the filament and its lead wires

Question: What function do small wires in a light bulb's stem perform?


Answer: kaolin

Context: Most light bulbs have either clear or coated glass. The coated glass bulbs have a white powdery substance on the inside called kaolin. Kaolin, or kaolinite, is a white, chalky clay in a very fine powder form, that is blown in and electrostatically deposited on the interior of the bulb. It diffuses the light emitted from the filament, producing a more gentle and evenly distributed light. Manufacturers may add pigments to the kaolin to adjust the characteristics of the final light emitted from the bulb. Kaolin diffused bulbs are used extensively in interior lighting because of their comparatively gentle light. Other kinds of colored bulbs are also made, including the various colors used for "party bulbs", Christmas tree lights and other decorative lighting. These are created by coloring the glass with a dopant; which is often a metal like cobalt (blue) or chromium (green). Neodymium-containing glass is sometimes used to provide a more natural-appearing light.

Question: What is the powdery substance in coated glass light bulbs?


Answer: blown in and electrostatically deposited

Question: How is kaolin placed inside a light bulb?


Answer: a more gentle and evenly distributed light

Question: What is the effect of a kaolin coating on the light cast?


Answer: by coloring the glass with a dopant

Question: How are Christmas colored light bulbs created?


Answer: It diffuses the light emitted from the filament

Question: How does kaolin create a more gentle light?


Answer: screw base

Context: Many arrangements of electrical contacts are used. Large lamps may have a screw base (one or more contacts at the tip, one at the shell) or a bayonet base (one or more contacts on the base, shell used as a contact or used only as a mechanical support). Some tubular lamps have an electrical contact at either end. Miniature lamps may have a wedge base and wire contacts, and some automotive and special purpose lamps have screw terminals for connection to wires. Contacts in the lamp socket allow the electric current to pass through the base to the filament. Power ratings for incandescent light bulbs range from about 0.1 watt to about 10,000 watts.

Question: What is the name for a base with one or more contacts at the tip and one at the shell?


Answer: bayonet base

Question: What is the name for a lamp base with one or more contacts on the base and a shell used as a contact or used only as a mechanical support?


Answer: allow the electric current to pass through the base to the filament

Question: What is the purpose of contacts in the lamp socket?


Answer: 0.1 watt to about 10,000 watts

Question: What is the range of power ratings for incandescent bulbs?


Answer: automotive and special purpose lamps

Question: Which types of lamps use screw terminals for connection to wires?


Answer: introduces heat losses (and therefore efficiency loss)

Context: The role of the gas is to prevent evaporation of the filament, without introducing significant heat losses. For these properties, chemical inertness and high atomic or molecular weight is desirable. The presence of gas molecules knocks the liberated tungsten atoms back to the filament, reducing its evaporation and allowing it to be operated at higher temperature without reducing its life (or, for operating at the same temperature, prolongs the filament life). It however introduces heat losses (and therefore efficiency loss) from the filament, by heat conduction and heat convection.

Question: What is a potential problem with the use of gas in a light bulb?


Answer: chemical inertness and high atomic or molecular weight

Question: What are the ideal chemical properties for the gas in a light bulb?


Answer: to prevent evaporation of the filament, without introducing significant heat losses

Question: What is the purpose of the gas in a light bulb?


Answer: The presence of gas molecules knocks the liberated tungsten atoms back to the filament

Question: How do gases prevent evaporation of the filament?


Answer: ribbon machine

Context: In manufacturing the glass bulb, a type of "ribbon machine" is used. A continuous ribbon of glass is passed along a conveyor belt, heated in a furnace, and then blown by precisely aligned air nozzles through holes in the conveyor belt into molds. Thus the glass bulbs are created. After the bulbs are blown, and cooled, they are cut off the ribbon machine; a typical machine of this sort produces 50,000 bulbs per hour. The filament and its supports are assembled on a glass stem, which is fused to the bulb. The air is pumped out of the bulb, and the evacuation tube in the stem press is sealed by a flame. The bulb is then inserted into the lamp base, and the whole assembly tested.

Question: What type of machine manufactures glass light bulbs.


Answer: 50,000

Question: How many bulbs does the average ribbon machine produce per hour?


Answer: assembled on a glass stem, which is fused to the bulb

Question: How is the filament attached to the bulb?


Answer: by a flame

Question: How is the evacuation tube sealed?


Answer: precisely aligned air nozzles

Question: What blows the glass bulbs into their characteristic shape?


Answer: carbon

Context: The first successful light bulb filaments were made of carbon (from carbonized paper or bamboo). Early carbon filaments had a negative temperature coefficient of resistance — as they got hotter, their electrical resistance decreased. This made the lamp sensitive to fluctuations in the power supply, since a small increase of voltage would cause the filament to heat up, reducing its resistance and causing it to draw even more power and heat even further. In the "flashing" process, carbon filaments were heated by current passing through them while in an evacuated vessel containing hydrocarbon vapor (usually gasoline). The carbon deposited on the filament by this treatment improved the uniformity and strength of filaments as well as their efficiency. A metallized or "graphitized" filament was first heated in a high-temperature oven before flashing and lamp assembly. This transformed the carbon into graphite which further strengthened and smoothed the filament. This also changed the filament to have a positive temperature coefficient, like a metallic conductor, and helped stabilize the lamp's power consumption, temperature and light output against minor variations in supply voltage.

Question: What material were the first light bulb filaments made from?


Answer: as they got hotter, their electrical resistance decreased

Question: What was the primary problem with early carbon filaments?


Answer: improved the uniformity and strength of filaments as well as their efficiency

Question: What were the positive effects of the flashing process?


Answer: further strengthened and smoothed the filament

Question: What properties of graphite improved the filament?


Answer: helped stabilize the lamp's power consumption, temperature and light output against minor variations in supply voltage

Question: What are the effects of giving the filament a positive temperature coefficient?


Answer: Siemens

Context: In 1902, the Siemens company developed a tantalum lamp filament. These lamps were more efficient than even graphitized carbon filaments and could operate at higher temperatures. Since tantalum metal has a lower resistivity than carbon, the tantalum lamp filament was quite long and required multiple internal supports. The metal filament had the property of gradually shortening in use; the filaments were installed with large loops that tightened in use. This made lamps in use for several hundred hours quite fragile. Metal filaments had the property of breaking and re-welding, though this would usually decrease resistance and shorten the life of the filament. General Electric bought the rights to use tantalum filaments and produced them in the US until 1913.

Question: What company invented the tantalum light filament?


Answer: 1902

Question: In what year was the tantalum light filament invented?


Answer: These lamps were more efficient than even graphitized carbon filaments and could operate at higher temperatures.

Question: What were the major advantages of the tantalum light filament?


Answer: General Electric

Question: Who purchased the rights to the tantalum light filament from Siemens?


Answer: 1913

Question: When did GE cease production of the tantalum light filament?


Answer: Tungsten metal was initially not available in a form that allowed it to be drawn into fine wires.

Context: In 1906, the tungsten filament was introduced. Tungsten metal was initially not available in a form that allowed it to be drawn into fine wires. Filaments made from sintered tungsten powder were quite fragile. By 1910, a process was developed by William D. Coolidge at General Electric for production of a ductile form of tungsten. The process required pressing tungsten powder into bars, then several steps of sintering, swaging, and then wire drawing. It was found that very pure tungsten formed filaments that sagged in use, and that a very small "doping" treatment with potassium, silicon, and aluminium oxides at the level of a few hundred parts per million greatly improved the life and durability of the tungsten filaments.

Question: What was the problem with manufacturing the tungsten filament?


Answer: William D. Coolidge

Question: Who developed the ductile form of tungsten?


Answer: 1910

Question: When was the ductile form of tungsten invented?


Answer: 1906

Question: When was the tungsten filament introduced?


Answer: potassium, silicon, and aluminium oxides

Question: What other materials were combined with tungsten?


Answer: 22.8 inches

Context: To improve the efficiency of the lamp, the filament usually consists of multiple coils of coiled fine wire, also known as a 'coiled coil'. For a 60-watt 120-volt lamp, the uncoiled length of the tungsten filament is usually 22.8 inches (580 mm), and the filament diameter is 0.0018 inches (0.046 mm). The advantage of the coiled coil is that evaporation of the tungsten filament is at the rate of a tungsten cylinder having a diameter equal to that of the coiled coil. The coiled-coil filament evaporates more slowly than a straight filament of the same surface area and light-emitting power. As a result, the filament can then run hotter, which results in a more efficient light source, while reducing the evaporation so that the filament will last longer than a straight filament at the same temperature.

Question: How long is a typical uncoiled tungsten filament for a 60-watt bulb?


Answer: The coiled-coil filament evaporates more slowly

Question: What is the advantage of a coiled-coil filament over a straight filament?


Answer: more efficient light source

Question: What positive effects does a slower-evaporating filament enable?


Answer: 0.0018 inches

Question: What is the typical diameter of the filament on a 60-watt bulb?


Answer: a variation of diameter of only 1% will cause a 25% reduction in service life

Context: One of the problems of the standard electric light bulb is filament notching due to evaporation of the filament. Small variations in resistivity along the filament cause "hot spots" to form at points of higher resistivity; a variation of diameter of only 1% will cause a 25% reduction in service life. These hot spots evaporate faster than the rest of the filament, which increases the resistance at that point—this creates a positive feedback that ends in the familiar tiny gap in an otherwise healthy-looking filament. Irving Langmuir found that an inert gas, instead of vacuum, would retard evaporation. General service incandescent light bulbs over about 25 watts in rating are now filled with a mixture of mostly argon and some nitrogen, or sometimes krypton. Lamps operated on direct current develop random stairstep irregularities on the filament surface which may cut lifespan in half compared to AC operation; different alloys of tungsten and rhenium can be used to counteract the effect.

Question: What is the negative effect of "hot spots" forming on the filament?


Answer: Irving Langmuir

Question: Who discovered that inert gas could slow evaporation?


Answer: argon and some nitrogen, or sometimes krypton

Question: Which gases are typically used in a light bulb?


Answer: alloys of tungsten and rhenium

Question: Which type of alloys can decrease "stairstep" irregularities in light bulb filaments?


Answer: conducts heat from the filament, thereby cooling the filament

Context: While inert gas reduces filament evaporation, it also conducts heat from the filament, thereby cooling the filament and reducing efficiency. At constant pressure and temperature, the thermal conductivity of a gas depends upon the molecular weight of the gas and the cross sectional area of the gas molecules. Higher molecular weight gasses have lower thermal conductivity, because both the molecular weight is higher and also the cross sectional area is higher. Xenon gas improves efficiency because of its high molecular weight, but is also more expensive, so its use is limited to smaller lamps.

Question: Why does inert gas reduce efficiency?


Answer: molecular weight of the gas and the cross sectional area of the gas molecules

Question: What affects the thermal conductivity of a gas?


Answer: Higher molecular weight gasses have lower thermal conductivity

Question: How does the molecular weight of a gas relate to thermal conductivity?


Answer: more expensive, so its use is limited to smaller lamps

Question: Why is xenon gas not more widely used?


Answer: reduces filament evaporation

Question: What is the advantage of using inert gas in a light bulb?


Answer: hotter, more-efficient filaments evaporate faster

Context: During ordinary operation, the tungsten of the filament evaporates; hotter, more-efficient filaments evaporate faster. Because of this, the lifetime of a filament lamp is a trade-off between efficiency and longevity. The trade-off is typically set to provide a lifetime of several hundred to 2,000 hours for lamps used for general illumination. Theatrical, photographic, and projection lamps may have a useful life of only a few hours, trading life expectancy for high output in a compact form. Long-life general service lamps have lower efficiency but are used where the cost of changing the lamp is high compared to the value of energy used.

Question: What determines how fast a tungsten filament evaporates?


Answer: several hundred to 2,000 hours

Question: What is the typical goal for the life of a tungsten filament bulb?


Answer: Theatrical, photographic, and projection lamps

Question: Which types of lamps may have particularly short lives?


Answer: efficiency and longevity

Question: What is the typical tradeoff in light bulb design?


Answer: the evaporated tungsten eventually condenses on the inner surface of the glass envelope

Context: In a conventional lamp, the evaporated tungsten eventually condenses on the inner surface of the glass envelope, darkening it. For bulbs that contain a vacuum, the darkening is uniform across the entire surface of the envelope. When a filling of inert gas is used, the evaporated tungsten is carried in the thermal convection currents of the gas, depositing preferentially on the uppermost part of the envelope and blackening just that portion of the envelope. An incandescent lamp that gives 93% or less of its initial light output at 75% of its rated life is regarded as unsatisfactory, when tested according to IEC Publication 60064. Light loss is due to filament evaporation and bulb blackening. Study of the problem of bulb blackening led to the discovery of the Edison effect, thermionic emission and invention of the vacuum tube.

Question: What darkens a conventional bulb over its lifetime?


Answer: An incandescent lamp that gives 93% or less of its initial light output at 75% of its rated life is regarded as unsatisfactory

Question: What is the IEC guideline for an unacceptable level of light loss?


Answer: Light loss is due to filament evaporation and bulb blackening

Question: What are the primary causes of light loss?


Answer: on the uppermost part of the envelope

Question: Where in the bulb is evaporated tungsten deposited when inert gas is used?


Answer: across the entire surface of the envelope

Question: Where in the bulb is evaporated tungsten deposited when a vacuum is used?


Answer: significantly increase darkening

Context: A very small amount of water vapor inside a light bulb can significantly affect lamp darkening. Water vapor dissociates into hydrogen and oxygen at the hot filament. The oxygen attacks the tungsten metal, and the resulting tungsten oxide particles travel to cooler parts of the lamp. Hydrogen from water vapor reduces the oxide, reforming water vapor and continuing this water cycle. The equivalent of a drop of water distributed over 500,000 lamps will significantly increase darkening. Small amounts of substances such as zirconium are placed within the lamp as a getter to react with any oxygen that may bake out of the lamp components during operation.

Question: How does water vapor inside a light bulb affect lamp darkening?


Answer: The oxygen attacks the tungsten metal, and the resulting tungsten oxide particles travel to cooler parts of the lamp.

Question: Why does water increase lamp darkening?


Answer: zirconium

Question: What is an example of a substance that is added to light bulbs to reduce this effect?


Answer: The equivalent of a drop of water distributed over 500,000 lamps

Question: How much water is necessary to result in this darkening affect?


Answer: reduces

Context: The halogen lamp reduces uneven evaporation of the filament and eliminates darkening of the envelope by filling the lamp with a halogen gas at low pressure, rather than an inert gas. The halogen cycle increases the lifetime of the bulb and prevents its darkening by redepositing tungsten from the inside of the bulb back onto the filament. The halogen lamp can operate its filament at a higher temperature than a standard gas filled lamp of similar power without loss of operating life. Such bulbs are much smaller than normal incandescent bulbs, and are widely used where intense illumination is needed in a limited space. Fiber-optic lamps for optical microscopy is one typical application.

Question: Does the halogen bulp increase, reduce, or have no effect on filament evaporation?


Answer: by redepositing tungsten from the inside of the bulb back onto the filament

Question: How does the halogen bulb decrease darkening over time?


Answer: higher

Question: Does a halogen bulb operate at a higher or lower temperature than an incandescent?


Answer: bulbs are much smaller than normal incandescent bulbs

Question: How does the size of a halogen bulb compare to an incandescent?


Answer: where intense illumination is needed in a limited space

Question: What is the most common situation when a halogen bulb is used?


Answer: an arc struck on a spherical bead electrode

Context: A variation of the incandescent lamp did not use a hot wire filament, but instead used an arc struck on a spherical bead electrode to produce heat. The electrode then became incandescent, with the arc contributing little to the light produced. Such lamps were used for projection or illumination for scientific instruments such as microscopes. These arc lamps ran on relatively low voltages and incorporated tungsten filaments to start ionization within the envelope. They provided the intense concentrated light of an arc lamp but were easier to operate. Developed around 1915, these lamps were displaced by mercury and xenon arc lamps.

Question: What did an alternate version of the incandescent lamp substitute for a wire filament?


Answer: scientific instruments such as microscopes

Question: What was a common application for this type of bulb?


Answer: 1915

Question: When was this style of lamp developed?


Answer: mercury and xenon arc lamps

Question: What displaced this style of lamp?


Answer: the actual power consumed (in watts) and the apparent power (in volt-amperes) are equal

Context: Incandescent lamps are nearly pure resistive loads with a power factor of 1. This means the actual power consumed (in watts) and the apparent power (in volt-amperes) are equal. Incandescent light bulbs are usually marketed according to the electrical power consumed. This is measured in watts and depends mainly on the resistance of the filament, which in turn depends mainly on the filament's length, thickness, and material. For two bulbs of the same voltage, type, color, and clarity, the higher-powered bulb gives more light.

Question: What does a power factor of 1 mean?


Answer: the resistance of the filament

Question: What principally determines the wattage of an incandescent bulb?


Answer: the filament's length, thickness, and material

Question: What determines the resistance of the filament?


Answer: Incandescent lamps are nearly pure resistive loads

Question: How close do incandescent lamps come to pure resistive loads?


Answer: the higher-powered bulb gives more light

Question: All other things being equal, how does wattage affect light emitted?


Answer: temperature

Context: The actual resistance of the filament is temperature dependent. The cold resistance of tungsten-filament lamps is about 1/15 the hot-filament resistance when the lamp is operating. For example, a 100-watt, 120-volt lamp has a resistance of 144 ohms when lit, but the cold resistance is much lower (about 9.5 ohms). Since incandescent lamps are resistive loads, simple phase-control TRIAC dimmers can be used to control brightness. Electrical contacts may carry a "T" rating symbol indicating that they are designed to control circuits with the high inrush current characteristic of tungsten lamps. For a 100-watt, 120-volt general-service lamp, the current stabilizes in about 0.10 seconds, and the lamp reaches 90% of its full brightness after about 0.13 seconds.

Question: What determines the resistance of a filament?


Answer: they are designed to control circuits with the high inrush current characteristic of tungsten lamps

Question: What does a "T" rating symbol on an electrical contact mean?


Answer: 0.13 seconds

Question: How long does it take a typical 100-watt bulb to achieve 90% of its brightness?


Answer: The cold resistance of tungsten-filament lamps is about 1/15 the hot-filament resistance

Question: How does the cold resistance of tungsten filament lamps compare to the hot resistance?


Answer: 144 ohms

Question: What is the resistance of a typical lit 100-watt incandescent bulb?


Answer: the shape of the bulb

Context: Incandescent light bulbs come in a range of shapes and sizes. The names of the shapes may be slightly different in some regions. Many of these shapes have a designation consisting of one or more letters followed by one or more numbers, e.g. A55 or PAR38. The letters represent the shape of the bulb. The numbers represent the maximum diameter, either in 1⁄8 of an inch, or in millimeters, depending on the shape and the region. For example, 63 mm reflectors are designated R63, but in the US, they are known as R20 (2.5 in). However, in both regions, a PAR38 reflector is known as PAR38.

Question: What do the letters identify in a bulb shape designation?


Answer: the maximum diameter

Question: What do the numbers identify in a bulb shape designation?


Answer: The names of the shapes may be slightly different in some regions

Question: Can the name of a certain bulb shape vary?


Answer: 1⁄8 of an inch, or in millimeters

Question: What units are the bulb sizes measured in?


Answer: General Electric

Context: Very small lamps may have the filament support wires extended through the base of the lamp, and can be directly soldered to a printed circuit board for connections. Some reflector-type lamps include screw terminals for connection of wires. Most lamps have metal bases that fit in a socket to support the lamp and conduct current to the filament wires. In the late 19th century, manufacturers introduced a multitude of incompatible lamp bases. General Electric introduced standard base sizes for tungsten incandescent lamps under the Mazda trademark in 1909. This standard was soon adopted across the US, and the Mazda name was used by many manufacturers under license through 1945. Today most incandescent lamps for general lighting service use an Edison screw in candelabra, intermediate, or standard or mogul sizes, or double contact bayonet base. Technical standards for lamp bases include ANSI standard C81.67 and IEC standard 60061-1 for common commercial lamp sizes, to ensure interchangeablitity between different manufacturer's products. Bayonet base lamps are frequently used in automotive lamps to resist loosening due to vibration. A bipin base is often used for halogen or reflector lamps.

Question: Which company introduced standard base sizes for incandescent lamps?


Answer: 1909

Question: In what year were standard base sizes introduced for incandescent lamps?


Answer: ANSI standard C81.67 and IEC standard 60061-1

Question: What are some common technical standards for lamp bases?


Answer: Bayonet base lamps

Question: What is the typical base type for automotive lamps?


Answer: bipin base

Question: What is the typical base type for halogen lamps?


Answer: a 5% reduction in operating voltage

Context: This means that a 5% reduction in operating voltage will more than double the life of the bulb, at the expense of reducing its light output by about 16%. This may be a very acceptable trade off for a light bulb that is in a difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings). Long-life bulbs take advantage of this trade-off. Since the value of the electric power they consume is much more than the value of the lamp, general service lamps emphasize efficiency over long operating life. The objective is to minimize the cost of light, not the cost of lamps. Early bulbs had a life of up to 2500 hours, but in 1924 a cartel agreed to limit life to 1000 hours. When this was exposed in 1953, General Electric and other leading American manufacturers were banned from limiting the life.

Question: What level of voltage reduction is required to double the life of an incandescent bulb?


Answer: 1924

Question: When did light bulb manufacturers establish a cartel to limit bulb life?


Answer: 1953

Question: When did authorities break up the light bulb cartel?


Answer: 1000 hours

Question: What was the artificially low limit on bulb life placed by the cartel?


Answer: difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings)

Question: What is an example of a good application for a long-life bulb?


Answer: 1901

Context: The relationships above are valid for only a few percent change of voltage around rated conditions, but they do indicate that a lamp operated at much lower than rated voltage could last for hundreds of times longer than at rated conditions, albeit with greatly reduced light output. The "Centennial Light" is a light bulb that is accepted by the Guinness Book of World Records as having been burning almost continuously at a fire station in Livermore, California, since 1901. However, the bulb emits the equivalent light of a four watt bulb. A similar story can be told of a 40-watt bulb in Texas that has been illuminated since 21 September 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, and was moved to an area museum in 1977.

Question: When did the "Centennial Light" begin burning?


Answer: the equivalent light of a four watt bulb

Question: How much light does the bulb emit?


Answer: 21 September 1908

Question: When did the long-lasting bulb in Texas begin continuing illumination?


Answer: an opera house

Question: Where did the Texas bulb begin its life?


Answer: 50 °C (122 °F)

Context: In flood lamps used for photographic lighting, the tradeoff is made in the other direction. Compared to general-service bulbs, for the same power, these bulbs produce far more light, and (more importantly) light at a higher color temperature, at the expense of greatly reduced life (which may be as short as two hours for a type P1 lamp). The upper temperature limit for the filament is the melting point of the metal. Tungsten is the metal with the highest melting point, 3,695 K (6,191 °F). A 50-hour-life projection bulb, for instance, is designed to operate only 50 °C (122 °F) below that melting point. Such a lamp may achieve up to 22 lumens per watt, compared with 17.5 for a 750-hour general service lamp.

Question: At what temperature does a typical 50-hour-life projection bulb operate?


Answer: Tungsten

Question: Which metal has the highest melting point?


Answer: as short as two hours

Question: What is the typical life of a P1 lamp?


Answer: higher color temperature

Question: How does the color temperature differ for photographic lighting?


Answer: 17.1 lumens per watt

Context: Lamps designed for different voltages have different luminous efficacy. For example, a 100-watt, 120-volt lamp will produce about 17.1 lumens per watt. A lamp with the same rated lifetime but designed for 230 V would produce only around 12.8 lumens per watt, and a similar lamp designed for 30 volts (train lighting) would produce as much as 19.8 lumens per watt. Lower voltage lamps have a thicker filament, for the same power rating. They can run hotter for the same lifetime before the filament evaporates.

Question: How many lumens per watt does a typical 100-watt, 120-volt lamp produce?


Answer: as much as 19.8 lumens per watt

Question: How many lumens per watt does a typical train light produce?


Answer: Lower voltage lamps have a thicker filament

Question: How does filament size relate to voltage level?


Answer: They can run hotter for the same lifetime before the filament evaporates.

Question: What is the effect of a thicker filament on bulb temperature?