Question: When was fluorescent lighting first available?

Forms of lighting include alcove lighting, which like most other uplighting is indirect. This is often done with fluorescent lighting (first available at the 1939 World's Fair) or rope light, occasionally with neon lighting, and recently with LED strip lighting. It is a form of backlighting.

Answer: 1939

Forms of lighting include alcove lighting, which like most other uplighting is indirect. <hl> This is often done with fluorescent lighting (first available at the 1939 World's Fair) or rope light, occasionally with neon lighting, and recently with LED strip lighting. <hl> It is a form of backlighting.

Forms of lighting include alcove lighting, which like most other uplighting is indirect. This is often done with fluorescent lighting (first available at the <hl> 1939 <hl> World's Fair) or rope light, occasionally with neon lighting, and recently with LED strip lighting. It is a form of backlighting.


Question: What type of lighting can be mounted in the ceiling to appear flush?

Recessed lighting (often called "pot lights" in Canada, "can lights" or 'high hats" in the US) is popular, with fixtures mounted into the ceiling structure so as to appear flush with it. These downlights can use narrow beam spotlights, or wider-angle floodlights, both of which are bulbs having their own reflectors. There are also downlights with internal reflectors designed to accept common 'A' lamps (light bulbs) which are generally less costly than reflector lamps. Downlights can be incandescent, fluorescent, HID (high intensity discharge) or LED.

Answer: Recessed lighting

<hl> Recessed lighting (often called "pot lights" in Canada, "can lights" or 'high hats" in the US) is popular, with fixtures mounted into the ceiling structure so as to appear flush with it. <hl> These downlights can use narrow beam spotlights, or wider-angle floodlights, both of which are bulbs having their own reflectors. There are also downlights with internal reflectors designed to accept common 'A' lamps (light bulbs) which are generally less costly than reflector lamps. Downlights can be incandescent, fluorescent, HID (high intensity discharge) or LED.

<hl> Recessed lighting <hl> (often called "pot lights" in Canada, "can lights" or 'high hats" in the US) is popular, with fixtures mounted into the ceiling structure so as to appear flush with it. These downlights can use narrow beam spotlights, or wider-angle floodlights, both of which are bulbs having their own reflectors. There are also downlights with internal reflectors designed to accept common 'A' lamps (light bulbs) which are generally less costly than reflector lamps. Downlights can be incandescent, fluorescent, HID (high intensity discharge) or LED.


Question: Peking man kindled fire as early as?

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

Answer: 400,000 BCE

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. <hl> As early as 400,000 BCE , fire was kindled in the caves of Peking Man. <hl> Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. As early as <hl> 400,000 BCE <hl>, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

As early as <hl> 400,000 BCE <hl> , fire was kindled in the caves of Peking Man.


Question: Which type of oily animals where also used as lamps after being threaded with wick?

Answer: birds and fish

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. <hl> Oily animals ( birds and fish ) were also used as lamps after being threaded with a wick. <hl> Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. Oily animals (<hl> birds and fish <hl>) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

Oily animals ( <hl> birds and fish <hl> ) were also used as lamps after being threaded with a wick.


Question: What is considered the earliest form of artificial lighting?

Answer: campfires or torches

<hl> With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches . <hl> As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were <hl> campfires or torches <hl>. As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were <hl> campfires or torches <hl> .


Question: The hollow worked stones lamps found in Lascaux caves date back how far?

Answer: 15,000 years

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. <hl> Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about 15,000 years ago. <hl> Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".

With the discovery of fire, the earliest form of artificial lighting used to illuminate an area were campfires or torches. As early as 400,000 BCE, fire was kindled in the caves of Peking Man. Prehistoric people used primitive oil lamps to illuminate surroundings. These lamps were made from naturally occurring materials such as rocks, shells, horns and stones, were filled with grease, and had a fiber wick. Lamps typically used animal or vegetable fats as fuel. Hundreds of these lamps (hollow worked stones) have been found in the Lascaux caves in modern-day France, dating to about <hl> 15,000 years <hl> ago. Oily animals (birds and fish) were also used as lamps after being threaded with a wick. Fireflies have been used as lighting sources. Candles and glass and pottery lamps were also invented. Chandeliers were an early form of "light fixture".


Question: What type of lighting was powered by electricity?

Major reductions in the cost of lighting occurred with the discovery of whale oil and kerosene. Gas lighting was economical enough to power street lights in major cities starting in the early 1800s, and was also used in some commercial buildings and in the homes of wealthy people. The gas mantle boosted the luminosity of utility lighting and of kerosene lanterns. The next major drop in price came about with the incandescent light bulb powered by electricity.

Answer: incandescent light

Major reductions in the cost of lighting occurred with the discovery of whale oil and kerosene. Gas lighting was economical enough to power street lights in major cities starting in the early 1800s, and was also used in some commercial buildings and in the homes of wealthy people. The gas mantle boosted the luminosity of utility lighting and of kerosene lanterns. <hl> The next major drop in price came about with the incandescent light bulb powered by electricity. <hl>

Major reductions in the cost of lighting occurred with the discovery of whale oil and kerosene. Gas lighting was economical enough to power street lights in major cities starting in the early 1800s, and was also used in some commercial buildings and in the homes of wealthy people. The gas mantle boosted the luminosity of utility lighting and of kerosene lanterns. The next major drop in price came about with the <hl> incandescent light <hl> bulb powered by electricity.


Question: When did gas powered street lights became economically available.

Answer: early 1800s

Major reductions in the cost of lighting occurred with the discovery of whale oil and kerosene. <hl> Gas lighting was economical enough to power street lights in major cities starting in the early 1800s , and was also used in some commercial buildings and in the homes of wealthy people. <hl> The gas mantle boosted the luminosity of utility lighting and of kerosene lanterns. The next major drop in price came about with the incandescent light bulb powered by electricity.

Major reductions in the cost of lighting occurred with the discovery of whale oil and kerosene. Gas lighting was economical enough to power street lights in major cities starting in the <hl> early 1800s <hl>, and was also used in some commercial buildings and in the homes of wealthy people. The gas mantle boosted the luminosity of utility lighting and of kerosene lanterns. The next major drop in price came about with the incandescent light bulb powered by electricity.

Gas lighting was economical enough to power street lights in major cities starting in the <hl> early 1800s <hl> , and was also used in some commercial buildings and in the homes of wealthy people.


Question: Street lights help reduce?

Over time, electric lighting became ubiquitous in developed countries. Segmented sleep patterns disappeared, improved nighttime lighting made more activities possible at night, and more street lights reduced urban crime.

Answer: urban crime.

Over time, electric lighting became ubiquitous in developed countries. <hl> Segmented sleep patterns disappeared, improved nighttime lighting made more activities possible at night, and more street lights reduced urban crime. <hl>

Over time, electric lighting became ubiquitous in developed countries. Segmented sleep patterns disappeared, improved nighttime lighting made more activities possible at night, and more street lights reduced <hl> urban crime. <hl>


Question: What can come in a wide variety of styles for various functions?

Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.

Answer: Lighting fixtures

<hl> Lighting fixtures come in a wide variety of styles for various functions. <hl> The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.

<hl> Lighting fixtures <hl> come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.


Question: Functioning as holder a light fixture can provide directed light and avoid?

Answer: visual glare

Lighting fixtures come in a wide variety of styles for various functions. <hl> The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare . <hl> Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.

Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid <hl> visual glare <hl>. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes.

The most important functions are as a holder for the light source, to provide directed light and to avoid <hl> visual glare <hl> .


Question: Luminous efficacy is measure in what unit?

An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the surroundings. The more transparent the lighting fixture is, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability.

Answer: lumen per watt

<hl> An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt . <hl> A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the surroundings. The more transparent the lighting fixture is, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability.

An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in <hl> lumen per watt <hl>. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the surroundings. The more transparent the lighting fixture is, the higher efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability.

An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in <hl> lumen per watt <hl> .


Question: How many Kelvins is daylight measured at?

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Answer: 6400

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. <hl> An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. <hl> Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around <hl> 6400 <hl> Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.


Question: What has a color temperature around 2800 to 3000 Kelvin?

Answer: incandescent bulb

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. <hl> An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. <hl> Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An <hl> incandescent bulb <hl> has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.


Question: It can be said that lights with a high color temperature have more energy in what color spectrum?

Answer: blue-white

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. <hl> Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. <hl> For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a <hl> blue-white <hl> appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.


Question: A lamp with more energy in the yellow and red spectrum are known to be?

Answer: Lower color temperature

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. <hl> Lower color temperature lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. <hl> For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.

Color temperature for white light sources also affects their use for certain applications. The color temperature of a white light source is the temperature in Kelvin of a theoretical black body emitter that most closely matches the spectral characteristics of the lamp. An incandescent bulb has a color temperature around 2800 to 3000 Kelvin; daylight is around 6400 Kelvin. <hl> Lower color temperature <hl> lamps have relatively more energy in the yellow and red part of the visible spectrum, while high color temperatures correspond to lamps with more of a blue-white appearance. For critical inspection or color matching tasks, or for retail displays of food and clothing, the color temperature of the lamps will be selected for the best overall lighting effect.


Question: A light is classified by intended purpose, what mainly changes its classification?

Answer: light produced by the fixture.

<hl> Lighting is classified by intended use as general, accent, or task lighting, depending largely on the distribution of the light produced by the fixture. <hl>

Lighting is classified by intended use as general, accent, or task lighting, depending largely on the distribution of the <hl> light produced by the fixture. <hl>


Question: Who invented track lighting?

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.

Answer: Lightolier

<hl> Track lighting, invented by Lightolier , was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. <hl> It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.

Track lighting, invented by <hl> Lightolier <hl>, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.

Track lighting, invented by <hl> Lightolier <hl> , was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall.


Question: What feeds all the fixtures in low voltage tracks instead of each light having a line-to-low voltage transformer.

Answer: master transformer

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. <hl> A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. <hl> There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A <hl> master transformer <hl> feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.


Question: What type of lighting uses lights that are hung or clipped to bare metal cables?

Answer: cable lighting

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. <hl> A modified version of this is cable lighting , where lights are hung from or clipped to bare metal cables under tension. <hl>

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is <hl> cable lighting <hl>, where lights are hung from or clipped to bare metal cables under tension.

A modified version of this is <hl> cable lighting <hl> , where lights are hung from or clipped to bare metal cables under tension.


Question: How many volts does a track lighting system usually use?

Answer: 12 or 24 volts

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. <hl> A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts , instead of each light fixture having its own line-to-low voltage transformer. <hl> There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.

Track lighting, invented by Lightolier, was popular at one period of time because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with <hl> 12 or 24 volts <hl>, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension.

A master transformer feeds all of the fixtures on the track or rod with <hl> 12 or 24 volts <hl> , instead of each light fixture having its own line-to-low voltage transformer.


Question: What is a uplight used for ambient lighting?

A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. A torchiere is an uplight intended for ambient lighting. It is typically a floor lamp but may be wall-mounted like a sconce.

Answer: torchiere

A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. <hl> A torchiere is an uplight intended for ambient lighting. <hl> It is typically a floor lamp but may be wall-mounted like a sconce.

A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. A <hl> torchiere <hl> is an uplight intended for ambient lighting. It is typically a floor lamp but may be wall-mounted like a sconce.


Question: What is one type of fixture commonly found in offices?

The portable or table lamp is probably the most common fixture, found in many homes and offices. The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting. Magnifier lamps are also task lighting.

Answer: table lamp

<hl> The portable or table lamp is probably the most common fixture, found in many homes and offices. <hl> The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting. Magnifier lamps are also task lighting.

The portable or <hl> table lamp <hl> is probably the most common fixture, found in many homes and offices. The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting. Magnifier lamps are also task lighting.


Question: Magnifier lamps are considered what type of lighting?

Answer: task lighting

The portable or table lamp is probably the most common fixture, found in many homes and offices. <hl> The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting . <hl> Magnifier lamps are also task lighting.

The portable or table lamp is probably the most common fixture, found in many homes and offices. The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered <hl> task lighting <hl>. Magnifier lamps are also task lighting.

The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered <hl> task lighting <hl> .


Question: When would neon lighting be considered general lighting?

The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. This would probably fall under accent lighting, though in a dark nightclub it could be considered general lighting.

Answer: dark nightclub

The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. <hl> This would probably fall under accent lighting, though in a dark nightclub it could be considered general lighting. <hl>

The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. This would probably fall under accent lighting, though in a <hl> dark nightclub <hl> it could be considered general lighting.


Question: What uses diffuser panels below fluorescent lights?

Answer: illuminated ceiling

<hl> The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. <hl> This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. This would probably fall under accent lighting, though in a dark nightclub it could be considered general lighting.

The <hl> illuminated ceiling <hl> was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. This would probably fall under accent lighting, though in a dark nightclub it could be considered general lighting.


Question: Normally neon lighting is considered what type of lighting?

Answer: accent lighting

The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. <hl> This would probably fall under accent lighting , though in a dark nightclub it could be considered general lighting. <hl>

The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else, but to actually be an artwork in itself. This would probably fall under <hl> accent lighting <hl>, though in a dark nightclub it could be considered general lighting.

This would probably fall under <hl> accent lighting <hl> , though in a dark nightclub it could be considered general lighting.


Question: What do steps in move theater aisles have for safety markings?

In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with LED based versions.

Answer: small lights

<hl> In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. <hl> Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with LED based versions.

In a movie theater, steps in the aisles are usually marked with a row of <hl> small lights <hl> for convenience and safety, when the film has started and the other lights are off. Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with LED based versions.


Question: What are the low wattage lamps being replaced with in movie theaters?

Answer: LED based versions

In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. <hl> Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with LED based versions . <hl>

In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with <hl> LED based versions <hl>.

Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube, these are rapidly being replaced with <hl> LED based versions <hl> .


Question: What kind of tube are the movie theaters lights enclosed in?

Answer: translucent tube

In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. <hl> Traditionally made up of small low wattage, low voltage lamps in a track or translucent tube , these are rapidly being replaced with LED based versions. <hl>

In a movie theater, steps in the aisles are usually marked with a row of small lights for convenience and safety, when the film has started and the other lights are off. Traditionally made up of small low wattage, low voltage lamps in a track or <hl> translucent tube <hl>, these are rapidly being replaced with LED based versions.

Traditionally made up of small low wattage, low voltage lamps in a track or <hl> translucent tube <hl> , these are rapidly being replaced with LED based versions.


Question: What is used to light walkways at night?

Street Lights are used to light roadways and walkways at night. Some manufacturers are designing LED and photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures.

Answer: Street Lights

<hl> Street Lights are used to light roadways and walkways at night. <hl> Some manufacturers are designing LED and photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures.

<hl> Street Lights <hl> are used to light roadways and walkways at night. Some manufacturers are designing LED and photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures.


Question: What kind of lights are being designed for energy efficiency?

Answer: photovoltaic luminaires

Street Lights are used to light roadways and walkways at night. <hl> Some manufacturers are designing LED and photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures. <hl>

Street Lights are used to light roadways and walkways at night. Some manufacturers are designing LED and <hl> photovoltaic luminaires <hl> to provide an energy-efficient alternative to traditional street light fixtures.


Question: What kind of light is used to illuminate outdoor playing fields at night?

Floodlights can be used to illuminate outdoor playing fields or work zones during nighttime hours. The most common type of floodlights are metal halide and high pressure sodium lights.

Answer: Floodlights

<hl> Floodlights can be used to illuminate outdoor playing fields or work zones during nighttime hours. <hl> The most common type of floodlights are metal halide and high pressure sodium lights.

<hl> Floodlights <hl> can be used to illuminate outdoor playing fields or work zones during nighttime hours. The most common type of floodlights are metal halide and high pressure sodium lights.


Question: Extremely bright lights used to deter crime are called?

Sometimes security lighting can be used along roadways in urban areas, or behind homes or commercial facilities. These are extremely bright lights used to deter crime. Security lights may include floodlights.

Answer: security lighting

<hl> Sometimes security lighting can be used along roadways in urban areas, or behind homes or commercial facilities. <hl> These are extremely bright lights used to deter crime. Security lights may include floodlights.

Sometimes <hl> security lighting <hl> can be used along roadways in urban areas, or behind homes or commercial facilities. These are extremely bright lights used to deter crime. Security lights may include floodlights.


Question: What type of light would be used illuminate the entrance to a property?

Entry lights can be used outside to illuminate and signal the entrance to a property. These lights are installed for safety, security, and for decoration.

Answer: Entry lights

<hl> Entry lights can be used outside to illuminate and signal the entrance to a property. <hl> These lights are installed for safety, security, and for decoration.

<hl> Entry lights <hl> can be used outside to illuminate and signal the entrance to a property. These lights are installed for safety, security, and for decoration.


Question: What color are tail lights?

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.

Answer: red

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. <hl> Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. <hl> White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are <hl> red <hl> and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.


Question: What color are headlamps on a vehicle?

Answer: white or selective yellow

Vehicles typically include headlamps and tail lights. <hl> Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. <hl> Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.

Vehicles typically include headlamps and tail lights. Headlamps are <hl> white or selective yellow <hl> lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.


Question: When did automakers start using electroluminescent technology to backlight gauges?

Answer: late 1950s

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. <hl> In the late 1950s , some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements. <hl>

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the <hl> late 1950s <hl>, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.

In the <hl> late 1950s <hl> , some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.


Question: What color are reversing indicator lamps?

Answer: White

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. <hl> White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. <hl> Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. <hl> White <hl> rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.


Question: What indicates that a driver is intending to change position?

Answer: turn signals

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. <hl> Flashing turn signals on the front, side, and rear of the vehicle indicate an intended change of position or direction. <hl> In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.

Vehicles typically include headlamps and tail lights. Headlamps are white or selective yellow lights placed in the front of the vehicle, designed to illuminate the upcoming road and to make the vehicle more visible. Many manufactures are turning to LED headlights as an energy-efficient alternative to traditional headlamps. Tail and brake lights are red and emit light to the rear so as to reveal the vehicle's direction of travel to following drivers. White rear-facing reversing lamps indicate that the vehicle's transmission has been placed in the reverse gear, warning anyone behind the vehicle that it is moving backwards, or about to do so. Flashing <hl> turn signals <hl> on the front, side, and rear of the vehicle indicate an intended change of position or direction. In the late 1950s, some automakers began to use electroluminescent technology to backlight their cars' speedometers and other gauges or to draw attention to logos or other decorative elements.


Question: What is the removable and replaceable part of a light fixture?

Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

Answer: light bulbs

<hl> Commonly called ' light bulbs ', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. <hl> While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

Commonly called '<hl> light bulbs <hl>', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

Commonly called ' <hl> light bulbs <hl> ', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation.


Question: What does a light bulb convert into electromagnetic radiation?

Answer: electrical energy

<hl> Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. <hl> While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts <hl> electrical energy <hl> into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.


Question: Huge much light does a 13 W compact fluorescent lamp produce equivalent to a incandescent light bulb.

Answer: 60 w

Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. <hl> A wax candle produces on the close order of 13 lumens, a 60 w att incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. <hl> Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a <hl> 60 w <hl>att incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

A wax candle produces on the close order of 13 lumens, a <hl> 60 w <hl> att incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens, but actual output varies by specific design.


Question: How many lemuns does a 15 watt fluorescent lamp produce?

Answer: 800 lumens

Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. <hl> A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about 800 lumens , but actual output varies by specific design. <hl> Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

Commonly called 'light bulbs', lamps are the removable and replaceable part of a light fixture, which converts electrical energy into electromagnetic radiation. While lamps have traditionally been rated and marketed primarily in terms of their power consumption, expressed in watts, proliferation of lighting technology beyond the incandescent light bulb has eliminated the correspondence of wattage to the amount of light produced. For example, a 60 W incandescent light bulb produces about the same amount of light as a 13 W compact fluorescent lamp. Each of these technologies has a different efficacy in converting electrical energy to visible light. Visible light output is typically measured in lumens. This unit only quantifies the visible radiation, and excludes invisible infrared and ultraviolet light. A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about <hl> 800 lumens <hl>, but actual output varies by specific design. Rating and marketing emphasis is shifting away from wattage and towards lumen output, to give the purchaser a directly applicable basis upon which to select a lamp.

A wax candle produces on the close order of 13 lumens, a 60 watt incandescent lamp makes around 700 lumens, and a 15-watt compact fluorescent lamp produces about <hl> 800 lumens <hl> , but actual output varies by specific design.


Question: What is designing as it applies to built environments?

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Answer: architectural lighting design

<hl> Lighting design as it applies to the built environment is known as ' architectural lighting design '. <hl> Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Lighting design as it applies to the built environment is known as '<hl> architectural lighting design <hl>'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Lighting design as it applies to the built environment is known as ' <hl> architectural lighting design <hl> '.


Question: Would you consider aesthetic elements alone in architectural lighting design?

Answer: kno

<hl> Lighting design as it applies to the built environment is kno wn as 'architectural lighting design'. <hl> Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Lighting design as it applies to the built environment is <hl> kno <hl>wn as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Lighting design as it applies to the built environment is <hl> kno <hl> wn as 'architectural lighting design'.


Question: What is the name of the software sometimes used to help calculate lighting needs in a built environment?

Answer: Radiance

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. <hl> More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design. <hl>

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as <hl> Radiance <hl> which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.


Question: Hand-calculations are based off of what type of data?

Answer: tabular

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. <hl> For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. <hl> More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on <hl> tabular <hl> data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.


Question: What type of factor calculation can be used to find out how much daylight is received in a internal space.

Answer: Daylight factor calculation.

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. <hl> Artificial lighting takes into account the amount of daylight received in an internal space by using Daylight factor calculation. For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. <hl> More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.

Lighting design as it applies to the built environment is known as 'architectural lighting design'. Lighting of structures considers aesthetic elements as well as practical considerations of quantity of light required, occupants of the structure, energy efficiency and cost. Artificial lighting takes into account the amount of daylight received in an internal space by using <hl> Daylight factor calculation. <hl> For simple installations, hand-calculations based on tabular data are used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer using software such as Radiance which can allow an Architect to quickly undertake complex calculations to review the benefit of a particular design.


Question: What type of paint tends to absorb light?

In some design instances, materials used on walls and furniture play a key role in the lighting effect< for example dark paint tends to absorb light, making the room appear smaller and more dim than it is, whereas light paint does the opposite. In addition to paint, reflective surfaces also have an effect on lighting design.

Answer: dark paint

<hl> In some design instances, materials used on walls and furniture play a key role in the lighting effect< for example dark paint tends to absorb light, making the room appear smaller and more dim than it is, whereas light paint does the opposite. <hl> In addition to paint, reflective surfaces also have an effect on lighting design.

In some design instances, materials used on walls and furniture play a key role in the lighting effect< for example <hl> dark paint <hl> tends to absorb light, making the room appear smaller and more dim than it is, whereas light paint does the opposite. In addition to paint, reflective surfaces also have an effect on lighting design.


Question: What kind of paint makes a room a room look larger and brighter?

Answer: light paint

<hl> In some design instances, materials used on walls and furniture play a key role in the lighting effect< for example dark paint tends to absorb light, making the room appear smaller and more dim than it is, whereas light paint does the opposite. <hl> In addition to paint, reflective surfaces also have an effect on lighting design.

In some design instances, materials used on walls and furniture play a key role in the lighting effect< for example dark paint tends to absorb light, making the room appear smaller and more dim than it is, whereas <hl> light paint <hl> does the opposite. In addition to paint, reflective surfaces also have an effect on lighting design.


Question: What type of study is used to simulate lighting designs?

Photometric studies (also sometimes referred to as "layouts" or "point by points") are often used to simulate lighting designs for projects before they are built or renovated. This enables architects, lighting designers, and engineers to determine whether a proposed lighting setup will deliver the amount of light intended. They will also be able to determine the contrast ratio between light and dark areas. In many cases these studies are referenced against IESNA or CIBSE recommended lighting practices for the type of application. Depending on the type of area, different design aspects may be emphasized for safety or practicality (i.e. such as maintaining uniform light levels, avoiding glare or highlighting certain areas). Specialized software is often used to create these, which typically combine the use of two-dimensional digital CAD drawings and lighting calculation software (i.e. AGi32or Dialux).

Answer: Photometric studies

<hl> Photometric studies (also sometimes referred to as "layouts" or "point by points") are often used to simulate lighting designs for projects before they are built or renovated. <hl> This enables architects, lighting designers, and engineers to determine whether a proposed lighting setup will deliver the amount of light intended. They will also be able to determine the contrast ratio between light and dark areas. In many cases these studies are referenced against IESNA or CIBSE recommended lighting practices for the type of application. Depending on the type of area, different design aspects may be emphasized for safety or practicality (i.e. such as maintaining uniform light levels, avoiding glare or highlighting certain areas). Specialized software is often used to create these, which typically combine the use of two-dimensional digital CAD drawings and lighting calculation software (i.e. AGi32or Dialux).

<hl> Photometric studies <hl> (also sometimes referred to as "layouts" or "point by points") are often used to simulate lighting designs for projects before they are built or renovated. This enables architects, lighting designers, and engineers to determine whether a proposed lighting setup will deliver the amount of light intended. They will also be able to determine the contrast ratio between light and dark areas. In many cases these studies are referenced against IESNA or CIBSE recommended lighting practices for the type of application. Depending on the type of area, different design aspects may be emphasized for safety or practicality (i.e. such as maintaining uniform light levels, avoiding glare or highlighting certain areas). Specialized software is often used to create these, which typically combine the use of two-dimensional digital CAD drawings and lighting calculation software (i.e. AGi32or Dialux).


Question: What is prepared prior to the performance for the lighting operator?

Lighting illuminates the performers and artists in a live theatre, dance, or musical performance, and is selected and arranged to create dramatic effects. Stage lighting uses general illumination technology in devices configured for easy adjustment of their output characteristics.[citation needed] The setup of stage lighting is tailored for each scene of each production. Dimmers, colored filters, reflectors, lenses, motorized or manually aimed lamps, and different kinds of flood and spot lights are among the tools used by a stage lighting designer to produce the desired effects. A set of lighting cues are prepared so that the lighting operator can control the lights in step with the performance; complex theatre lighting systems use computer control of lighting instruments.

Answer: lighting cues

Lighting illuminates the performers and artists in a live theatre, dance, or musical performance, and is selected and arranged to create dramatic effects. Stage lighting uses general illumination technology in devices configured for easy adjustment of their output characteristics.[citation needed] The setup of stage lighting is tailored for each scene of each production. Dimmers, colored filters, reflectors, lenses, motorized or manually aimed lamps, and different kinds of flood and spot lights are among the tools used by a stage lighting designer to produce the desired effects. <hl> A set of lighting cues are prepared so that the lighting operator can control the lights in step with the performance; complex theatre lighting systems use computer control of lighting instruments. <hl>

Lighting illuminates the performers and artists in a live theatre, dance, or musical performance, and is selected and arranged to create dramatic effects. Stage lighting uses general illumination technology in devices configured for easy adjustment of their output characteristics.[citation needed] The setup of stage lighting is tailored for each scene of each production. Dimmers, colored filters, reflectors, lenses, motorized or manually aimed lamps, and different kinds of flood and spot lights are among the tools used by a stage lighting designer to produce the desired effects. A set of <hl> lighting cues <hl> are prepared so that the lighting operator can control the lights in step with the performance; complex theatre lighting systems use computer control of lighting instruments.


Question: Motion pictures employee the similar lighting techniques as which other form of lighting?

Motion picture and television production use many of the same tools and methods of stage lighting. Especially in the early days of these industries, very high light levels were required and heat produced by lighting equipment presented substantial challenges. Modern cameras require less light, and modern light sources emit less heat.

Answer: stage lighting

<hl> Motion picture and television production use many of the same tools and methods of stage lighting . <hl> Especially in the early days of these industries, very high light levels were required and heat produced by lighting equipment presented substantial challenges. Modern cameras require less light, and modern light sources emit less heat.

Motion picture and television production use many of the same tools and methods of <hl> stage lighting <hl>. Especially in the early days of these industries, very high light levels were required and heat produced by lighting equipment presented substantial challenges. Modern cameras require less light, and modern light sources emit less heat.

Motion picture and television production use many of the same tools and methods of <hl> stage lighting <hl> .


Question: What is the basic SI unit of measurement?

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

Answer: candela (cd)

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. <hl> The basic SI unit of measurement is the candela (cd) , which describes the luminous intensity, all other photometric units are derived from the candela. <hl> Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the <hl> candela (cd) <hl>, which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

The basic SI unit of measurement is the <hl> candela (cd) <hl> , which describes the luminous intensity, all other photometric units are derived from the candela.


Question: What is the SI unit for lumiance?

Answer: cd/m2

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. <hl> The SI unit for luminance is candela per square metre ( cd/m2 ). <hl> The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (<hl> cd/m2 <hl>). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

The SI unit for luminance is candela per square metre ( <hl> cd/m2 <hl> ).


Question: What is the CGS unit of lumiance?

Answer: stilb

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). <hl> The CGS unit of luminance is the stilb , which is equal to one candela per square centimetre or 10 kcd/m2. <hl> The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the <hl> stilb <hl>, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm).

The CGS unit of luminance is the <hl> stilb <hl> , which is equal to one candela per square centimetre or 10 kcd/m2.


Question: What is the amount of useful light emitted from a luminous flux measured in?

Answer: lumen (lm)

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. <hl> The amount of useful light emitted from a source or the luminous flux is measured in lumen (lm) . <hl>

Measurement of light or photometry is generally concerned with the amount of useful light falling on a surface and the amount of light emerging from a lamp or other source, along with the colors that can be rendered by this light. The human eye responds differently to light from different parts of the visible spectrum, therefore photometric measurements must take the luminosity function into account when measuring the amount of useful light. The basic SI unit of measurement is the candela (cd), which describes the luminous intensity, all other photometric units are derived from the candela. Luminance for instance is a measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area, and falls within a given solid angle. The SI unit for luminance is candela per square metre (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimetre or 10 kcd/m2. The amount of useful light emitted from a source or the luminous flux is measured in <hl> lumen (lm) <hl>.

The amount of useful light emitted from a source or the luminous flux is measured in <hl> lumen (lm) <hl> .