The degree of freedom per molecule for a gas on average is 8. If the gas performs 100 J of work when it expands under constant pressure, then the amount of heat absorbed by the gas is:
1. 500 J
2. 600 J
3. 20 J
4. 400 J

ABCA is a cyclic process. Its P-V graph would be:

1.		2.
3.		4.

In the P-V diagram shown, the gas does 5 J of work in the isothermal process ab and 4 J in the adiabatic process bc. What will be the change in internal energy of the gas in the straight path from c to a? 

1. 9J 

2. 1 J

3. 4 J 

4. 5 J

1 kg of gas does 20 kJ of work and receives 16 kJ of heat when it is expanded between two states. The second kind of expansion can be found between the same initial and final states, which requires a heat input of 9 kJ. The work done by the gas in the second expansion will be:

The pressure of a monoatomic gas increases linearly from $4\times {10}^5$ N/m² to $8\times {10}^5$ N/m² when its volume increases from 0.2 m³ to 0.5 m³. The work done by the gas is:

1. $2.8\times {10}^5 \mathrm{J}$

2. $1.8\times {10}^6 \mathrm{J}$

3. $1.8\times {10}^5 \mathrm{J}$

4. $1.8\times {10}^2 \mathrm{J}$

The figure below shows two paths that may be taken by a gas to go from state A to state C. In process AB, \(400~\text{J}\) of heat is added to the system and in process BC, \(100~\text{J}\) of heat is added to the system. The heat absorbed by the system in the process AC will be:

The latent heat of vaporisation of water is \(2240~\text{J/gm}\). If the work done in the process of expansion of \(1~\text{g}\) is \(168~\text{J}\), then the increase in internal energy is:
1. \(2408~\text{J}\)
2. \(2240~\text{J}\)
3. \(2072~\text{J}\)
4. \(1904~\text{J}\)

An ideal heat engine working between temperatures T₁ and T₂ has an efficiency η. The new efficiency if both the source and sink temperatures are doubled will be:
1. $\frac{\eta }{2}$
2. η
3. 2η
4. 3η

A monoatomic ideal gas, initially at temperature \(T_1\), is enclosed in a cylinder fitted with a frictionless piston. The gas is allowed to expand adiabatically to a temperature \(T_2\) by releasing the piston suddenly. If \(L_1\) and \(L_2\) are the lengths of the gas column before and after expansion, respectively, then \(\frac{T_1}{T_2}\) is given by:
1. \(\left(\frac{L_1}{L_2}\right)^{\frac{2}{3}}\)
2. \(\frac{L_1}{L_2}\)
3. \(\frac{L_2}{L_1}\)
4. \(\left(\frac{L_2}{L_1}\right)^{\frac{2}{3}}\)

The initial pressure and volume of a gas are \(P\) and \(V\), respectively. First, it is expanded isothermally to volume \(4V\) and then compressed adiabatically to volume \(V\). The final pressure of the gas will be: [Given: \(\gamma = 1.5\)]