1. Absorptive power of perfectly black body is

2. A black body at hot temperature at 227°C radiates heat at a rate of 5 cal/cm²s. at a temperature of 727°C the rate of heat radiated per unit area will be

3. A body cools from 50°C to 46°C in 5 minutes and to 40°C in the next 10 minutes. The surrounding temperature is

4. For which of the following process, the thermal conduction is maximum?

5. A bucket full of hot water is kept in a room and it cools from 75°C to 70°C in t1 minutes from 70°C to 65°C in t2 minutes and from 65°C to 60°C in t3 minutes; then

6. The good absorber of heat are

7. Two stars A and B radiate maximum energy at 3600°A and 3600°A respectively. Then the ratio of absolute temperatures of A and B is

8. A person with dark skin as compared to a person with white skin will experience

9. A cup of tea cools from 80°C to 60°C in one minute. The ambient temperature is 30°C. in cooling from 60°C to 50°C, it will take.

10. The best ideal black body is