Practice portal › Kinetic Theory of Gases › Specific Heats and the Ratio Gamma

To raise the temperature of a certain mass of gas by 50°C at constant pressure, 160 calories of heat is required. When the same mass of gas is cooled by 100°C at constant volume, 240 calories of heat is released. How many degrees of freedom does each molecule of this gas have (assume gas to be ideal)?

Asked in JEE Main 3rd Sept 2nd Shift 2020 · Cv, Cp and Mayer's relation

Answer: (2) 6

Step-by-step solution

At constant pressure: nC_P(50)=160, so nC_P=3.2 cal/K.

At constant volume: nC_V(100)=240, so nC_V=2.4 cal/K.

The unknown amount of gas cancels in the ratio: γ=(3.2)/(2.4)=4/3.

f=2/(γ-1)=2/(1/3).

f=6.

Why the other options are wrong

More Specific Heats and the Ratio Gamma questionsAll Specific Heats and the Ratio Gamma questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer