A refrigerator works between 4°C and 30°C. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required is (Take, 1 cal = 4.2 Joules)

(1)23.65W

(2)236.5W

(3)2365W

(4)2.365W

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-

(a) 380 J 
(b) 500 J
(c) 460 J
(d) 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 is taken through the cycle ABCD as shown in figure. Heat rejected by the gas during the cycle is 

(a)2 pV                                     (b)4 pV

(c)$\frac{1}{2}pV$                                    (d)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 -

An ideal gas goes from state A to state B via three different processes, as indicated in the P-V diagram. If ${\mathrm{Q}}_1,$ ${\mathrm{Q}}_2,$ ${\mathrm{Q}}_3$ indicates the heat absorbed by the gas along the three processes and $∆{\mathrm{U}}_1,$ $∆{\mathrm{U}}_2,$ $∆{\mathrm{U}}_3$ indicates the change in internal energy along the three processes respectively, then:

A mass of diatomic gas ($\gamma$=1.4) at a pressure of 2 atm is compressed adiabatically so that its temperature rise from $27°\mathrm{C}$ to $927°\mathrm{C}.$ The pressure of the gas is final state is-

(1) 28 atm                                           

(2) 68.7 atm

(3) 256 atm                                           

(4) 8 atm

In thermodynamic processes, which of the following statements is not true?

If Q, E and W denote respectively the heat added, change in internal energy and the work done in a closed cyclic process, then

(1) W=0                                 

(2) Q=W=0

(3) E=0                                   

(4) Q=0