An ungraduated thermometer of uniform bore is attached to a centimetre scale and is found to read 10.3 cm in melting ice, 26.8 cm in boiling water and 6.5 cm. in freezing mixture. The temperature of the freezing mixture will be :
-23.003o C
-23.03o C
-23.3o C
-23.33o 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
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
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
For a gas, the difference between two principal specific heats is 4150 J kg-1 K-1 . What is the specific heat of the gas at constant volume if the ratio of specific heats is 1.4 ?
5186 J kg-1 K-1
10375 J kg-1 K-1
1060 J kg-1 K-1
8475 J kg-1 K-1
A body cools from 60°C to 50°C in 10min. If room temperature is 25°C , the temperature of the body at the end of next 10 min will be
38.5°C
42.8°C
40°C
45°C
A black body radiates heat energy at the rate of 2 × 105 J/s/m2 at a temperature of 127°C. The temperature of black body at which the rate of radiation is 32 × 105 J/s/m2 is
527°C
273°C
873°C
927°C
Heat capacity of a body is infinite. It means
heat is given out
heat is taken in
no change in temperature whether heat is taken in or given out
All of these
A black body has maximum wavelength λm at 2000 K. Its corresponding wavelength at 3000 K will be