What is the difference between the two principal specific heats of 1 g of helium gas at S.T.P. ? Given molecular weight of helium = 4 and J=4.186 J cal-1 and R=8.31 J mol-1 K-1 .
0.586 cal g-1 K-1
0.496 cal g-1 K-1
0.782 cal g-1 K-1
0.576 cal g-1 K-1
Water falls from a height of 500 m. What is the rise in temperature of water at the bottom if the whole energy is used up in heating water ?
0.96o C
1.02o C
1.16o C
0.25o C
A black body has maximum wavelength λm at 2000 K. Its corresponding wavelength at 3000 K will be
During constant temperature, we feel colder on the day when the relative humidity is
85%
60%
50%
25%
540 g of ice at 0o C is mixed with 540 g of water at 80o C. The final temperature of the mixture is
40o C
79.9o C
80o C
0o C
A thermometer has wrong calibration. It reads the melting point of ice as - 10o C, the temperature of boiling point of water on this scale is :
-20o C
-40o C
-10o C
-10.7o C
If the temperature of the sun is doubled, the rate of energy received on earth will be increased by a factor of
2
4
8
16
A person weighing 60 kg taken in 2000 kcal diet in a day. If this energy were to be used in heating the person without any losses, what would be his rise in temperature ? (sp. heat of human body is 0.83 cal/gm/o C )
40.16o C
44.23o C
49.99o C
47.23o C
A sphere is at a temperature of 600K. Its cooling rate is R' in an external environment of 200 K. If temperature falls to 400 K, then cooling rate R' will be
3R/16
16R/3
9R/27
none of these
Wien's law states that :
T + λm = constant
λm T= constant
λm/T = constant
T4/ λm = constant
