Thermodynamics

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Question

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Question 1 :

A thermodynamically system is changed from state (P1, V1) to (P², V²) by two different processes, the quantity which will remain same is:

1. ΔQ
2. ΔW
3. ΔQ + ΔW
4. ΔQ – ΔW
Answer
8353

Question 2 : The temperatures of inside and outside of a refrigerator are 273 K and 303 K respectively. Assuming, that the refrigerator cycle is reversible, for every joule of work done, the heat delivered to the surrounding will be nearly:
1. 10 J
2. 20 J
3. 30 J
4. 50 J
Answer
8354

Question 3 : An engine has an efficiency of 1/6. When the temperature of sink is reduced by 62°C, its efficiency is doubled. Temperature of the source is:
1. 99°C
2. 62°C
3. 37°C
4. 124°C
Answer
8355

Question 4 : A black body at a temperature of 227°C radiates heat at the rate of 20 cal m^-2s-1. When its temperature rises to 727°C, the heat radiated will be
1. 40 units
2. 160 units
3. 320 units
4. 640 units
Answer
8356

Question 5 :

Which of the following is incorrect regarding the first law of thermodynamics? A. It is not applicable to any cyclic process
B. It is a restatement of the principle of conservation of energy
C. It introduces the concept of the internal energy
D. It introduces the concept of the entropy

1. A and D
2. B and C
3. C and A
4. A and B
Answer
8357