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

What were the positive effects of the flashing process?
What is the answer?
ANS: improved the uniformity and strength of filaments as well as their efficiency
QUES: In 2002, Elizabeth marked her Golden Jubilee. Her sister and mother died in February and March respectively, and the media speculated whether the Jubilee would be a success or a failure. She again undertook an extensive tour of her realms, which began in Jamaica in February, where she called the farewell banquet "memorable" after a power cut plunged the King's House, the official residence of the governor-general, into darkness. As in 1977, there were street parties and commemorative events, and monuments were named to honour the occasion. A million people attended each day of the three-day main Jubilee celebration in London, and the enthusiasm shown by the public for the Queen was greater than many journalists had expected.

How many people saw Elizabeth when she was in Jamaica?
What is the answer?
ANS: unanswerable
QUES: This idea was later developed in ancient philosophy by the Stoic school. Stoic epistemology generally emphasized that the mind starts blank, but acquires knowledge as the outside world is impressed upon it. The doxographer Aetius summarizes this view as "When a man is born, the Stoics say, he has the commanding part of his soul like a sheet of paper ready for writing upon." Later stoics, such as Sextus of Chaeronea, would continue this idea of empiricism in later Stoic writings as well. As Sextus contends "For every thought comes from sense-perception or not without sense-perception and either from direct experience or not without direct experience" (Against the Professors, 8.56-8).

Where was Aetius from?
What is the answer?
ANS:
unanswerable