The initial pressure and volume of a gas are P and V respectively. First, its volume is expanded to 4V by an isothermal process and then compressed adiabatically to volume V. The final pressure will be (γ = 1.5):
1. | 8P | 2. | 4P |
3. | P | 4. | 2P |
One mole of an ideal gas at an initial temperature of \(T\) K does \(6R\) joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is \(5/3\), the final temperature of the gas will be:
1. \((T-2.4)\) K
2. \((T+4)\) K
3. \((T-4)\) K
4. \((T+2.4)\) K
1. | \(\Delta {U}=-{W}\) in an isothermal process. |
2. | \(\Delta {U}={W}\) in an isothermal process. |
3. | \(\Delta {U}=-{W}\) in an adiabatic process. |
4. | \(\Delta {U}={W}\) in an adiabatic process. |
If a gas changes volume from 2 litres to 10 litres at a constant temperature of 300K, then the change in its internal energy will be:
1. | 12 J | 2. | 24 J |
3. | 36 J | 4. | 0 J |
When volume changes from \(V\) to \(2V\) at constant pressure(\(P\)), the change in internal energy will be:
1. \(PV\)
2. \(3PV\)
3. \(\frac{PV}{\gamma -1}\)
4. \(\frac{RV}{\gamma -1}\)
An ideal gas heat engine operates in a Carnot cycle between 227ºC and 127ºC. It absorbs 6 × 104 cals of heat at higher temperatures.
The amount of heat converted to work will be?
1. 4.8 × 104 cals
2. 2.4 × 104 cals
3. 1.2 × 104 cals
4. 6 × 104 cals
Which one of the following processes is reversible?
1. | Transfer of heat by radiation |
2. | Transfer of heat by conduction |
3. | Isothermal compression |
4. | Electrical heating of a nichrome wire |
A monoatomic gas at pressure P1 and volume V1 is compressed adiabatically to 1/8th its original volume. What is the final pressure of the gas?
1. P1
2. 16 P1
3. 32 P1
4. 64 P1
At a pressure of \(2\) atmospheres, a mass of diatomic gas \((\gamma = 1.4)\), is compressed adiabatically, causing its temperature to rise from \(27^{\circ}\mathrm{C}\) to \(927^{\circ}\mathrm{C}\). The pressure of the gas in the final state is:
1. 8 atm
2. 28 atm
3. 68.7 atm
4. 256 atm
An ideal gas goes from state \(A\) to state \(B\) via three different processes as indicated in the \((P\text-V)\) diagram.
If \(Q_1,Q_2,Q_3\) indicate the heat absorbed by the gas along the three processes and \(\Delta U_1, \Delta U_2, \Delta U_3\) indicate the change in internal energy along the three processes respectively, then:
1. | \(Q_3>Q_2>Q_1\) and \(\Delta U_1= \Delta U_2= \Delta U_3\) |
2. | \(Q_1=Q_2=Q_3\) and \(\Delta U_1> \Delta U_2> \Delta U_3\) |
3. | \(Q_3>Q_2>Q_1\) and \(\Delta U_1> \Delta U_2> \Delta U_3\) |
4. | \(Q_1>Q_2>Q_3\) and \(\Delta U_1= \Delta U_2= \Delta U_3\) |