A thermodynamic system undergoes a cyclic process \(ABCDA\) as shown in Fig. The work done by the system in the cycle is:
1. \( P_0 V_0 \)
2. \( 2 P_0 V_0 \)
3. \( \frac{P_0 V_0}{2} \)
4. zero
1. | \(1000~\text{J}\) | 2. | zero |
3. | \(-2000~\text{J}\) | 4. | \(2000~\text{J}\) |
1. | \(\frac{R}{\gamma -1}\) | 2. | \(\frac{\gamma -1}{R}\) |
3. | \(\gamma R \) | 4. | \(\frac{\left ( \gamma -1 \right )R}{\left ( \gamma +1 \right )}\) |
A thermodynamic system is taken through the cycle \(\mathrm{ABCD}\) as shown in the figure. Heat rejected by the gas during the cycle is:
1. \(2 {PV}\)
2. \(4{PV}\)
3. \(\frac{1}{2}{PV}\)
4. \(PV\)
One mole of an ideal gas goes from an initial state \(A\) to the final state \(B\) with 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:
1. | 2. | ||
3. | 4. |
When \(1\) kg of ice at \(0^{\circ}\) C melts into the water at \(0^{\circ}\) C, the resulting change in its entropy, taking the latent heat of ice to be \(80\) cal/gm, is:
1. \(8\times 10^4\) cal/K
2. \(80\) cal/K
3. \(293\) cal/K
4. \(273\) cal/K
During an isothermal expansion, a confined ideal gas does -150 J of work against its surrounding. This implies that:
1. | 300 J of heat has been added to the gas. |
2. | no heat is transferred because the process is isothermal. |
3. | 150 J of heat has been added to the gas. |
4. | 150 J of heat has been removed from the gas. |
The internal energy change in a system that has absorbed \(2\) kcal of heat and done \(500\) J of work is:
1. \(8900\) J
2. \(6400\) J
3. \(5400\) J
4. \(7900\) J
An engine has an efficiency of . When the temperature of the sink is reduced by , its efficiency is doubled. the temperature of the source is:
1. 124oC
2. 37oC
3. 62oC
4. 99oC
A Carnot engine whose sink is at \(300~\mathrm{K}\) has an efficiency of \(40\)%. By how much should the temperature of the source be increased to increase its efficiency by \(50\)% of its original efficiency?
1. | \(275~\mathrm{K}\) | 2. | \(325~\mathrm{K}\) |
3. | \(250~\mathrm{K}\) | 4. | \(380~\mathrm{K}\) |