During an adiabatic process, the volume of a gas is found to be proportional to the cube of its absolute temperature. The ratio C_p / C_V for the gas is

• 5/3

• 4/3

• 3/2

• 5/4

The work done by a gas is maximum when it expands

• isothermally

• adiabatically

• isentropically

• isobarically

An ideal monoatomic gas at 27°C is compressed adiabatically to 8/27 times of its present volume. The increase in temperature of the gas is

• 375°C

• 402°C

• 175°C

• 475°C

Blowing air with open mouth is an example of

• isobaric process

• isochoric process

• isothermal process

• adiabatic process

An ideal gas heat engine operates in a Carnot's cycle between 227°C and 127°C. It absorbs 6 x 10⁴ J at high temperature. The amount of heat converted into work is

• 1.6 × 10⁴ J

• 1.2 × 10⁴ J

• 4.8 × 10⁴ J

• 3.5 × 10⁴ J

A monoatomic gas is suddenly compressed to (1/8) of its initial volume adiabatically. The ratio of its final pressure to the initial pressure is : (Given the ratio of the specific heats of the given gas to be 5/3)

• 32

• 40/3

• 24/5

• 8

A Carnot engine takes heat from a reservoir at 627° C and rejects heat to a sink at 27°C. Its efficiency will be

• 3/5

• 1/3

• 2/3

• 200/209

58.

During an adiabatic process, the cube of the pressure is found to be inversely proportional to the fourth power of the volume. Then the ratio of specific heats is

• 1

• 1.33

• 1.67

• 1.4

A Carnot's engine operates with source at 127°C and sink at 27°C. If the source supplies 40 kJ of heat energy, the work done by the engine is

• 30 kJ

• 10 kJ

• 4 kJ

• 1 kJ

If γ is the ratio of specific heats and R is the universal gas constant, then the molar specific heat at constant volume C_V is given by

• γR

• $\frac{\left(\mathrm{\gamma } - 1\right) \mathrm{R}}{\mathrm{\gamma }}$

• $\frac{\mathrm{R}}{\mathrm{\gamma } - 1}$

• $\frac{\mathrm{\gamma R}}{\mathrm{\gamma } - 1}$