Thermodynamics (Physics)

Given are statements for certain thermodynamic variables, Choose the correct answer from the options given below :

1. C and D Only
2. A and B Only
3. D and A Only
4. B and C Only

The volume of an ideal gas ( = 1.5) is changed adiabatically from 5 litres to 4 litres. The ratio of initial pressure to final pressure is :

1. 45
2. 85 5
3. 2 5
4. 1625

A sample of 1 mole gas at temperature T is adiabatically expanded to double its volume. If adiabatic constant for the gas is = 32, then the work done by the gas in the process is :

1. RT[2 + 2]
2. RT[2 - 2]
3. RT[2 - 2]
4. TR[2 + 2]

A real gas within a closed chamber at 27 undergoes the cyclic process as shown in figure. The gas obeys PV3 = RT equation for the path A to B. The net work done in the complete cycle is (assuming R = 8 J/mol K): [figure]

1. -20 J
2. 205 J
3. 225 J
4. 20 J

Two different adiabatic paths for the same gas intersect two isothermal curves as shown in P-V diagram. The relation between the ratio VaVd and the ratio VbVc is: [figure]

1. VaVd VbVc
2. VaVd = ( VbVc )-1
3. VaVd = VbVc
4. VaVd = ( VbVc )2

A diatomic gas ( = 1.4) does 100 J of work in an isobaric expansion. The heat given to the gas is :

1. 150 J
2. 490 J
3. 350 J
4. 250 J

The specific heat at constant pressure of a real gas obeying PV2 = RT equation is:

1. R
2. CV + R
3. CV + R2V
4. R3 + CV

A total of 48 J heat is given to one mole of helium kept in a cylinder. The temperature of helium increases by 2 C. The work done by the gas is: Given, R = 8.3 J K-1 mol-1.

1. 23.1 J
2. 48 J
3. 24.9 J
4. 72.9 J

The heat absorbed by a system in going through the given cyclic process is : [figure]

1. 61.6 J
2. 431.2 J
3. 19.6 J
4. 616 J

During an adiabatic process, if the pressure of a gas is found to be proportional to the cube of its absolute temperature, then the ratio of CPCV for the gas is :

1. 53
2. 32
3. 75
4. 97