# 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, the pressure remains constant. 3. In an isothermal process, the temperature remains constant. 4. In an adiabatic process, $$P V^\gamma$$ = constant.

Subtopic:  Types of Processes |
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In isothermal expansion, the pressure is determined by:

 1 Temperature only 2 Compressibility only 3 Both temperature and compressibility 4 None of these

Subtopic:  Types of Processes |
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Under isothermal conditions, the volumes of ideal gas A and actual gas B grow from V to 2 V. The increase in internal energy:

 1 will be the same in both A and B. 2 will be zero in both the gases. 3 of B will be more than that of A. 4 of A will be more than that of B.

Subtopic:  Molar Specific Heat |
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The specific heat of a gas in an isothermal process is:
1. Infinite
2. Zero
3. Negative
4. Remains constant

Subtopic:  Molar Specific Heat |
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The pressure and density of a diatomic gas $\left(\gamma =7/5\right)$ changes adiabatically from (P, d) to (P', d'). If $\frac{d\text{'}}{d}=32$, then $\frac{P\text{'}}{P}$ should be:

 1 1/128 2 32 3 128 4 None of the above
Subtopic:  Types of Processes |
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Two identical samples of a gas are allowed to expand, (i) isothermally and (ii) adiabatically. Work done will be:

 1 more in the isothermal process. 2 more in the adiabatic process. 3 equal in both processes. 4 none of the above.

Subtopic:  Work Done by a Gas |
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In an adiabatic expansion of a gas, if the initial and final temperatures are $$T_1$$ and $$T_2$$, respectively, then the change in internal energy of the gas is:
1. $$\frac{nR}{\gamma-1}(T_2-T_1)$$
2. $$\frac{nR}{\gamma-1}(T_1-T_2)$$
3. $$nR ~(T_1-T_2)$$
4. Zero

Subtopic:  First Law of Thermodynamics |
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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 – 2.4)K

3. (T + 4)K

4. (T – 4)K

Subtopic:  Work Done by a Gas |
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In a cyclic process, the internal energy of the gas:

 1 Increases 2 Decreases 3 Remains constant 4 Becomes zero
Subtopic:  Cyclic Process |
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In a Carnot engine, when $$T_2=0^\circ \mathrm{C}$$ and $$T_1=200^\circ \mathrm{C},$$ its efficiency is $$\eta_1$$ and when $$T_1=0^\circ \mathrm{C}$$ and $$T_2=-200^\circ \mathrm{C},$$ its efficiency is $$\eta_2.$$ What is the value of $$\frac{\eta_1}{\eta_2}?$$

 1 0.577 2 0.733 3 0.638 4 cannot be calculated
Subtopic:  Carnot Engine |
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