Traditional Culture Encyclopedia - Photography and portraiture - When the bulb glows, the temperature measured in the bulb is 100℃ and the pressure is 1 atm. When the temperature is 20℃, the bulb does not emit light, and the internal air pressure is

When the bulb glows, the temperature measured in the bulb is 100℃ and the pressure is 1 atm. When the temperature is 20℃, the bulb does not emit light, and the internal air pressure is

Solution: T 1=273+ 100K=373K, T2=273+20K=293K.

The volume change of gas in a light bulb is equal, which is obtained by Charlie's law:

P 1/T 1 =P2/T2

Therefore, p2 = (T2/t1) p1= 0.79p1.

So the answer is: 0.79