\(1\) g of water of volume \(1\) cm3 at \(100^\circ \text{C}\) is converted into steam at the same temperature under normal atmospheric pressure \(\approx 1\times10^{5} \) Pa. The volume of steam formed equals \(1671\) cm3. If the specific latent heat of vaporization of water is \(2256\) J/g, the change in internal energy is:
1. \(2423\) J
2. \(2089\) J
3. \(167\) J
4. \(2256\) J
1. | isochoric | 2. | isothermal |
3. | adiabatic | 4. | isobaric |
The molar specific heat at a constant pressure of an ideal gas is \(\dfrac{7}{2}R.\) The ratio of specific heat at constant pressure to that at constant volume is:
1. | \(\dfrac{7}{5}\) | 2. | \(\dfrac{8}{7}\) |
3. | \(\dfrac{5}{7}\) | 4. | \(\dfrac{9}{7}\) |
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. | \(380~\mathrm{K}\) |
If \(Q\), \(E\), and \(W\) denote respectively the heat added, the change in internal energy, and the work done in a closed cycle process, then:
1. | \(W=0\) | 2. | \(Q=W=0\) |
3. | \(E=0\) | 4. | \(Q=0\) |
In thermodynamic processes which of the following statements is not true?
1. | In an adiabatic process, the system is insulated from the surroundings. |
2. | In an isochoric process, pressure remains constant. |
3. | In an isothermal process, the temperature remains constant. |
4. | In an adiabatic process \(PV^\gamma=\mathrm{constant}.\) |
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
If \(\Delta U\) and \(\Delta W\) represent the increase in internal energy and work done by the system respectively in a thermodynamical process, which of the following is true?
1. | \(\Delta U=-\Delta W\), in an adiabatic process |
2. | \(\Delta U=\Delta W\) , in an isothermal process |
3. | \(\Delta U=\Delta W\), in an adiabatic process |
4. | \(\Delta U=-\Delta W\), in an isothermal process |
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. |
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