Thermal Properties of Matter

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Question

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Question 1 : Absorptive power of perfectly black body is
1. Zero
2. One
3. Infinity
4. Constant
Answer
8334

Question 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
1. 50 cal/cm²s
2. 80 cal/cm²s
3. 100 cal/cm²s
4. 250 cal/cm²s
Answer
8335

Question 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
1. 30°C
2. 28°C
3. 32°C
4. 36°C
Answer
8336

Question 4 : For which of the following process, the thermal conduction is maximum?
1. Radiation
2. Combustion
3. Convection
4. Conduction
Answer
8337

Question 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
1. t1 – t2 = t3
2. t1 > t2 > t3
3. t1 < t2 > t3
4. t1 < t2 < t3
Answer
8338