Exams › JEE Main › Physics

A vessel at temperature T contains N molecules of gas A, each having mass m, and 2N molecules of gas B, each having mass 2m. If the mean square speed of molecules of gas B is V2 and that of gas A is V1, then the ratio V1/V2 equals

1. 2
2. 1
3. 1/3
4. 2/3

Correct answer: 2

Solution

V1 = <v^2>_A = 3kT/m and V2 = <v^2>_B = 3kT/(2m). So V1/V2 = (3kT/m)/(3kT/2m) = 2.

Related JEE Main Physics questions

• An ideal gas is enclosed in a thermally insulated sealed container. During an adiabatic expansion, the mean interval between successive molecular collisions varies with the volume V as V^q. What is the value of q in terms of γ = Cp/Cv?
• At 300 K, the root mean square speed of hydrogen molecules is 1930 m/s. What will be the r.m.s. speed of oxygen molecules at 1200 K?
• A gaseous mixture contains 2 moles of oxygen and 4 moles of argon at temperature T. If vibrational degrees of freedom are ignored, what is the total internal energy of the mixture?
• If all intermolecular attractions were removed, what volume would be occupied by the molecules present in 4.5 g of water at standard temperature and pressure?
• An ideal gas sample has volume V, pressure P, and absolute temperature T. If the mass of one molecule is m, which expression gives the density of the gas?
• The speed of sound in oxygen (O₂) at a certain temperature is 460 m s⁻¹. The speed of sound in helium (He) at the same temperature will be (assume both gases to be ideal)

⚔️ Practice JEE Main Physics free + battle 1v1 →