The rms speed of the molecules of an enclosed gas is \(v\). What will be the rms speed if the pressure is doubled, keeping the temperature constant?

1.	\(v \over 2\)	2.	\(v\)
3.	\(2v\)	4.	\(4v\)

The ratio of number of collisions per second at the walls of containers by He and O₂ gas molecules kept at the same volume and temperature is: (assume normal incidence on walls)

(1) 2: 1

(2) 1: 2

(3) $2\sqrt{2}$: 1

(4) 1: $2\sqrt{2}$

An ant is moving on a plane horizontal surface. The number of degrees of freedom of the ant will be:

(1) 1

(2) 2

(3) 3

(4) 6

If a gas has 'f' degree of freedom, the ratio of the specific heats of the gases, $\frac{{\mathrm{C}}_{\mathrm{P}}}{{\mathrm{C}}_{\mathrm{V}}}$ is

(1) $\frac{1+\mathrm{f}}{2}$

(2) $1+\frac{\mathrm{f}}{2}$

(3) $1+\frac{1}{\mathrm{f}}$

(4) $1+\frac{2}{\mathrm{f}}$

Molar specific heat at constant volume, for a non-linear triatomic gas is: (vibration mode neglected)

(1) 3R

(2) 4R

(3) 2R

(4) R

A mixture of ideal gases has 2 moles of He, 4 moles of oxygen and 1 mole of ozone at absolute temperature T. The internal energy of the mixture is:

(1) 13RT

(2) 11RT

(3) 16RT

(4) 14RT

E₀ and E_H respectively represent the average kinetic energy of a molecule of oxygen and hydrogen. If the two gases are at the same temperature, which of the following statement is true?

(1) E₀  > E_H

(2) E₀  = E_H

(3) E₀  < E_H

(4) Data insufficient

14 g of CO at 27 ^oC is mixed with 16 g of O₂ at 47 ^oC. The temperature of the mixture is: (vibration mode neglected)

(1) - 5 ^oC

(2) 32 ^oC

(3) 37 ^oC

(4) 27 ^oC

When one mole of a monatomic gas is mixed with one mole of a diatomic gas, then the equivalent value of $\gamma$ for the mixture will be: (vibration mode neglected)

(1) 1.33

(2) 1.40

(3) 1.50

(4) 1.6

A box of negligible mass containing 2 moles of an ideal gas of molar mass M and adiabatic exponent $\gamma$ moves with constant speed v on a smooth horizontal surface. If the box suddenly stops, then the change in the temperature of the gas will be:

(1) $\frac{(\mathrm{\gamma }-1){\mathrm{Mv}}^2}{4\mathrm{R}}$

(2) $\frac{{\mathrm{\gamma Mv}}^2}{2\mathrm{R}}$

(3) $\frac{{\mathrm{Mv}}^2}{2(\mathrm{\gamma }-1)\mathrm{R}}$

(4) $\frac{(\mathrm{\gamma }-1){\mathrm{Mv}}^2}{2\mathrm{R}}$