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
A copper block of mass 2.5 kg is heated in a furnace to a temperature of 500o C and then placed on a large ice block. The maximum amount of ice that can melt is :(sp.heat of Cu = 0.39 J/gm/o C and heat of diffusion of water = 335 J/gm)
1.53 kg
1.50 kg
1.55 kg
1.6 kg
Wien's law states that :
T + λm = constant
λm T= constant
λm/T = constant
T4/ λm = constant
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
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
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
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
The volume of a liquid is 830 m3 at 30o C and it is 850 m3 at 90o C. The coefficient of volume expansion of the liquid is
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