Assuming the sun to be a spherical body of radius R at a temperature of TK, evaluate the total radiant power, incident on earth, at a distance r from the sun ?

( r₀ is the radius of the earth and  is the Stefan's constant.)

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 :

The earth radiates in the infra-red region of the spectrum. The spectrum is correctly given by :

Compared to burn due to air at 100^oC, a burn due to steam at 100^oC is :

According to Newton's law of cooling, the rate of cooling of a body is proportional to , where  is the difference of the temperature of the body and the surroundings and n is equal to:

A thermometer has wrong calibration.  It reads the melting point of ice as - 10^o C, the temperature of boiling point of water on this scale is :

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 ?

Wien's law states that :

Let 50 g of ice at 0^oC is mixed with 50 g of water at 80^oC, final temperature of mixture of will be:

A block of ice at - 10^oC is slowly heated and converted to steam at 100^oC. Which of the following curves represents the phenomenon qualitatively ?