Thermodynamics (Physics)

The work done in an adiabatic change in an ideal gas depends upon only :

1. change in its pressure
2. change in its temperature
3. change in its specific heat
4. change in its volume

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the correct answer from the options given below:

1. (A) is true but (R) is false
2. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
3. (A) is false but (R) is true
4. Both (A) and (R) are true and (R) is the correct explanation of (A)

A poly-atomic molecule (CV=3R, CP=4R, where R is gas constant) goes from phase space point A ( PA=105 Pa, VA=4 10-6 m3 ) to point B ( PB=5 104 Pa, VB=6 10-6 m3 ) to point C ( PC=104 Pa, VC=8 10-6 m3 ). A to B is an adiabatic path and B to C is an isothermal path. The net heat absorbed per unit mole by the system is : [figure]

1. 500R( 3+ 4)
2. 450R( 4- 3)
3. 500R 2
4. 400R 4

A Carnot engine (E) is working between two temperatures 473 K and 273 K. In a new system two engines - engine E1 works between 473 K to 373 K and engine E2 works between 373 K to 273 K. If 12, 1 and 2 are the efficiencies of the engines E, E1 and E2, respectively, then

1. 12 = 1 2
2. 12 = 1 + 2
3. 12 1 + 2
4. 12 < 1 + 2

An ideal gas goes from an initial state to final state. During the process, the pressure of gas increases linearly with temperature. Choose the correct answer from the options given below:

1. A, C Only
2. A, D, E Only
3. E Only
4. A, B, C, D Only

The temperature of 1 mole of an ideal monoatomic gas is increased by 50 at constant pressure. The total heat added and change in internal energy are E1 and E2, respectively. If E1E2= x9 then the value of x is .

The magnitude of heat exchanged by a system for the given cyclic process ABCA (as shown in figure) is (in SI unit) : [figure]

1. zero
2. 40
3. 5
4. 10

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). In the light of the above statements, choose the correct answer from the options given below :

1. Both (A) and (R) are true and (R) is the correct explanation of (A)
2. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)
3. (A) is false but (R) is true
4. (A) is true but (R) is false

Match List - I with List - II Choose the correct answer from the options given below:

1. A-I, B-III, C-II, D-IV
2. A-I, B-IV, C-II, D-III
3. A-III, B-I, C-IV, D-II
4. A-III, B-IV, C-I, D-II

An ideal gas initially at 0 temperature, is compressed suddenly to one fourth of its volume. If the ratio of specific heat at constant pressure to that at constant volume is 3/2, the change in temperature due to the thermodynamic process is K.