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A sample of 0.1 g of water at 100 $°C$ and normal pressure $\left(1.013\times {10}^5 N{m}^{-2}\right)$ requires 54 cal of heat energy to convert to steam at 100 $°C$. If the volume of the steam produced is 167.1 cc, the change in internal energy of the sample, is
1. 104.3 J
2. 208.7 J
3. 84.5 J
4. 42.2 J

The volume (V) of a monoatomic gas varies with its temperature (T), as shown in the graph. The ratio of work one by the gas, to the heat absorbed by it, when it undergoes a change from state A to state B, is

1.  $\frac{2}{5}$
2.  $\frac{2}{3}$
3.  $\frac{2}{7}$
4.  $\frac{1}{3}$

The efficiency of an ideal heat engine working between the freezing point and boiling point of water is
1.  26.8%
2.  20%
3.  12.5%
4.  6.25% 

A Carnot engine having an efficiency of $\frac{1}{10}$ as heat engine is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at a lower temperature is
1.  1 J
2.  90 J
3.  99 J
4.  100 J 

Thermodynamic processes are indicated in the following diagram.

1. P → a, Q → c, R → d, S → b
2. P → c, Q → a, R → d, S → b
3. P → c, Q → d, R → b, S → a
4. P → d, Q → b, R → a, S → C

One mole of an ideal monatomic gas undergoes a process described by the equation $P{V}^3$ = constant. The heat capacity of the gas during this process is
1.  $\frac{3}{2}R$
2.  $\frac{5}{2}R$
3.  2R
4.  R

The temperature inside a refrigerator is ${\mathrm{t}}_2$°C and the room temperature is ${\mathrm{t}}_1$°C. The amount of heat delivered to the room for each joule of electrical energy consumed ideally will be
1. $\frac{{\mathrm{t}}_1}{{\mathrm{t}}_1 - {\mathrm{t}}_2}$
2. $\frac{{\mathrm{t}}_1 + 273}{{\mathrm{t}}_1 - {\mathrm{t}}_2}$
3. $\frac{{\mathrm{t}}_2 + 273}{{\mathrm{t}}_1 - {\mathrm{t}}_2}$
4. $\frac{{\mathrm{t}}_1 +{\mathrm{t}}_2}{{\mathrm{t}}_1 - {\mathrm{t}}_2}$

A refrigerator works between $4°C$ and $30°C$. It is required to remove 600 calories of heat every second in order to keep the temperature of the refrigerated space constant. The power required us [Take 1 cal = 4.2 J)
1.  2365 W
2.  2.365 W
3.  23.65 W
4.  236.5 W 

A gas is compressed isothermally to half its initial volume. The same gas is compressed separately through an adiabatic process until its volume is again reduced to half. Then
1.  Which of the case (whether compression through isothermal or through the adiabatic process) requires more work will depend upon the automaticity of the gas
2.  Compressing the gas isothermally will require more work to be done
3.  Compressing the gas through the adiabatic process will require more work to be done 
4.  Compressing the gas isothermally or adiabatically will require the same amount of work 

4.0 g of a gas occupies 22.4 liters at NTP. The specific heat capacity of the gas at constant volume is 5.0 ${\mathrm{JK}}^{-1}$ ${\mathrm{mol}}^{-1}$, If the speed of sound in this gas at NTP is 952 ${\mathrm{ms}}^{-1}$, then the heat capacity at constant pressure is (Take gas constant R = 8.3 ${\mathrm{JK}}^{-1}$ ${\mathrm{mol}}^{-1}$)
1. 8.5 ${\mathrm{JK}}^{-1}$ ${\mathrm{mol}}^{-1}$
2. 8.0 ${\mathrm{JK}}^{-1}$ ${\mathrm{mol}}^{-1}$
3. 7.5 ${\mathrm{JK}}^{-1}$ ${\mathrm{mol}}^{-1}$
4. 7.0 ${\mathrm{JK}}^{-1}$ ${\mathrm{mol}}^{-1}$

The coefficient of performance of a refrigerator is 5. If the temperature inside the freezer is $-20°C$, the temperature of the surroundings to which it rejects heat is 
1.  20$°$C
2.  31$°$C
3.  41$°$C
4.  11$°$C

An ideal gas is compressed to half its initial volume by means of several processes. Which of the process results in the maximum work done on the gas?
1.  Isothermal
2.  Adiabatic
3.  Isobaric
4.  isochoric 

One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in the figure P (in kPa)

The change in internal energy of the gas during the transition is
1.  -12 kJ
2.  20 kJ
3.  -20 kJ
4.  20 J 

A Carnot engine, having an efficiency of $\eta = \frac{1}{10}$ as heat engine, is used as a refrigerator. If the work done on the system is 10 J, the amount of energy absorbed from the reservoir at lower temperature is
1.  1 J
2.  100 J
3.  99 J
4.  90 J 
 

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

1.  300 J
2.  380 J
3.  500 J
4.  460 J 
 

A monoatomic gas at a pressure P, having a volume V expands isothermally to a volume 2V and then adiabatically to a volume 16V. the final pressure of the gas is : (take y = 5/3)
1.  64P
2.  32P
3.  P/64
4.  16P 

A thermodynamic system undergoes cyclic process ABCDA as shown in the figure. The work done by the system in the cycle is

1. ${\mathrm{P}}_0{\mathrm{V}}_0$
2. $2{\mathrm{P}}_0{\mathrm{V}}_0$
3. $\frac{{\mathrm{P}}_0{\mathrm{V}}_0}{2}$
4. Zero

The molar specific heats of an ideal gas at constant pressure and volume are denoted by ${\mathrm{C}}_{\mathrm{P}} \mathrm{and} {\mathrm{C}}_{\mathrm{V}}$ respectively. If y = $\frac{{\mathrm{C}}_{\mathrm{P}}}{{\mathrm{C}}_{\mathrm{V}}}$ and R is the universal gas constant, then ${\mathrm{C}}_{\mathrm{V}}$ is equal to
1. $\frac{\mathrm{R}}{\mathrm{\gamma } - 1}$
2. $\frac{\mathrm{\gamma } - 1}{\mathrm{R}}$
3. $\mathrm{\gamma R}$
4. $\frac{1 + \mathrm{\gamma }}{1 - \mathrm{\gamma }}$

During an adiabatic process, the pressure of a gas is foPund to be proportional of a gas is found to be proportional to the cube of its temperature. The ratio of $\frac{c_P}{c_V}$ for the gas is :
1.  2
2.  $\frac{5}{3}$
3.  $\frac{3}{2}$
4.  $\frac{4}{3}$