A charged particle moves through a magnetic field perpendicular to its direction. Then

• the momentum changes but the kinetic energy is constant

• both momentum and kinetic energy of the particle are not constant

• both, momentum and kinetic energy of the particle are constant

• kinetic energy changes but the momentum is constant

A gaseous mixture consists of 16 g of helium and 16 g of oxygen. The ratio c_p/c_v of the mixture is

• 1.59

• 1.62

• 1.4

• 1.54

B.

1.62

Cp and Cv are specific heats at constant pressure and constant volume respectively. It is observed that
Cp – Cv = a for hydrogen gas
Cp – Cv = b for nitrogen gas
The correct relationship between a and b is

• a = 14 b

• a = 28 b

• a = 1/14b

• a= b

One mole of ideal monoatomic gas (γ = 5/30) is mixed with one mole of diatomic gas(γ = 7/5). What is γ for the mixture? γ denotes the ratio of specific heat at constant pressure, to that at constant volume.

• 3/2

• 23/15

• 35/23

• 4/3

The speed of sound in oxygen (O₂) at a certain temperature is 460 ms⁻¹. The speed of sound in helium (He) at the same temperature will be (assumed both gases to be ideal)

• 1420 ms⁻¹

• 550 ms⁻¹

• 375 ms⁻¹

• 650  ms⁻¹

A.

1420 ms⁻¹