A carnot engine having an efficiency of $\frac{1}{10}$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 

Figure below shows two paths that may be taken by a gas to go from a state A to a state C. In process AB, 400 J of heat is added to the system and in process BC, 100 J of heat is added to the system. The heat absorbed by the system in the process AC will be-

1. 380 J 
2. 500 J
3. 460 J
4. 300 J

One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in the figure.

The change in internal energy of the gas during the transition is

1. 20 kJ
 

2. -20 kJ
 

3. 20 J
 

4. -12 kJ

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 thermodynamic system undergoes cyclic process ABCDA as shown in figure. The work done by the system in the cycle is

1. ρ_oV_o 
 

2. 2ρ_oV_o
 

3. ρ_oV_o/2
 

4. zero

A gas is taken through the cycle A→B→C→A, as shown. What is the net work done by the gas?

1. 2000J
2. 1000J
3. Zero
4. -2000J

During an adiabatic process, the pressure of a gas is found to be proportional to the cube of its temperature. The ratio of C_P/C_V for the gas is equal to:

A thermodynamic system is taken through the cycle ABCD as shown in figure. Heat rejected by the gas during the cycle is 

1. 2 pV                                     
2. 4 pV
3. $\frac{1}{2}pV$                                   
4. pV

One mole of an ideal gas from an initial state A undergoes via two processes. It first undergoes isothermal expansion from volume V to 3V and then its volume is reduced from 3V to V at constant pressure. The correct P-V diagram representing the two processes is -

1. 
2. 
3. 
4.