NCERT Solutions for Class 11 Physics Physics Part Ii Chapter 13 Kinetic Theory

State Boyle's Law?

Calculate the degrees of freedom for monoatomic, diatomic and triatomic gas?

what do you mean by mean free path and write the formula?

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 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

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 mass of a hydrogen molecule is 3.32 x 10^-27 kg. If 10²³ hydrogen molecules strike, per second, a fixed wall of area 2cm² at an angle of 45° to the normal, and rebound elastically with a speed of 10³ m/s, then the pressure on the wall is nearly:

• 4.70 x 10² N/m²

• 2.35 x 10³ N /m²

• 4.70 x 10³ N/m²

• 2.35 x 10² N /m²

A particle is moving in a circular path of radius a under the action of an attractive potential U = -k/2r². its total energy is:

• $-\frac{3}{2}\frac{k}{a^2}$

• $\frac{-k}{4a^2}$

• $\frac{k}{2a^2}$

• zero

The kinetic energies of a planet in an elliptical orbit about the Sun, at positions A, B and C are K_A, K_B and K_C, respectively. AC is the major axis and SB is perpendicular to AC at the position of the Sun S as shown in the figure. Then

• K_A < K_B < K_C

• K_A > K_B > K_C

• K_B > K_A > K_C

• K_B < K_A < K_C