Kinetic Theory

JEE Main level, single correct, medium

102 of 168

Question 102 of 168

When heat QQ is supplied to a diatomic gas of rigid molecules, at constant volume its temperature increases by ∆T∆T . The heat required to produce the same change in temperature, at a constant pressure is:

Show answer and solution

Answer: (B) 75Q\dfrac{7}{5}Q

For diatomic gas CP=72R{C}_{P}=\dfrac{7}{2}R
CV=52R{C}_{V}=\dfrac{5}{2}R
Heat supplied at constant volume
Q=nCVΔTQ=n{C}_{V}\Delta T
Heat supplied at constant pressure
Q′=nCPΔT{Q}^{'}=n{C}_{P}\Delta T
QQ′=CVCP\dfrac{Q}{{Q}^{'}}=\dfrac{{C}_{V}}{{C}_{P}}
Q′=QCPCV=75Q{Q}^{'}=Q\dfrac{{C}_{P}}{{C}_{V}}=\dfrac{7}{5}Q

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Kinetic Theory (Degree of Freedom and Specific Heat), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.