A carnot engine having an efficiency of th of heat engine, is used as a refrigerator. If then work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is:
1. 1 J
2. 90 J
3. 99 J
4. 100 J
The temperature inside a refrigerator is and the room temperature is . The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be:
1.
2.
3.
4.
The coefficient of performance of a refrigerator is 5. If the temperature inside freezer is -20°C, the temperature of the surroundings to which it rejects heat is -
1. 31°C
2. 41°C
3. 11°C
4. 21°C
A Carnot engine working between 300 K and 600K has work output of 800 J per cycle. What is amount of heat energy supplied to the engine from source per cycle ?
(1) 1800 J/cycle
(2) 1000 J/cycle
(3) 2000 J/cycle
(4) 1600 J/cycle
A Carnot's engine used first an ideal monoatomic gas then an ideal diatomic gas. If the source and sink temperature are 411°C and 69°C respectively and the engine extracts 1000 J of heat in each cycle, then area enclosed by the PV diagram is -
(1) 100 J
(2) 300 J
(3) 500 J
(4) 700 J