Part 2 Thermo

The quantity PV/kT (k = Boltzmann’s constant) represents:

• Number of moles of the gas

• Total mass of the gas

• Number of molecules in the gas

• Density of the gas

In the process PV = constant, the pressure P versus density graph ρ of an ideal gas is

• A parabola

• A straight line passing through origin

• A straight line parallel to ρ-axis

• A straight line parallel to P-axis

The V_rms of gas molecules is 300 m/sec. If its absolute temperature is reduced to half and molecular weight is doubled, the V_rms will become

• 75 m/s

• 150 m/s

• 300 m/s

• 600 m/s

Average kinetic energy of molecules is

• Directly proportional to square root of temperature

• Directly proportional to absolute temperature

• Independent of absolute temperature

• Inversely proportional to absolute temperature

The specific heat of a gas in an isothermal process is

• Zero

• Negative

• Remains constant

• Infinite

1.      The specific heat of a gas in an adiabatic process is

• Zero

• Negative

• Remains constant

• Infinite

An ideal gas is taken in a sealed container at 300 K. it is heated at constant volume to a temperature 600 K. the mean kinetic energy of its molecules is

• Halved

• Doubled

• Tripled

• Quadrupled

If 70 calories heat is required to raise the temperature of 2 moles of an ideal diatomic gas at constant pressure from 30°C to 35°C. the amount of heat required to raise the temperature of the same gas through the same range at constant volume is

• 30 cal

• 50 cal

• 70 cal

• 90 cal

Which of the following is the unit of specific heat

• J kg/°C

• J/kg°C

• kg °C/J

• J kg/°C²

The mean free path of a gas molecule is λ₁ at temperature T. The pressure and temperature of the gas are made two times their original values. The new men's free path λ₂ is:

• Two times of λ₁

• Equal to λ₁

•  Half of λ₁

• Four times of λ₁