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Physics

Kinetic Theory

Kinetic theory links gas pressure to molecular motion, then builds out degrees of freedom, equipartition of energy, and mean free path. Most NEET questions ask for a single formula: rms speed, average kinetic energy, or a gas's molar specific heat.

Exam rules change between cycles. Confirm dates, syllabus and pattern against NTA's official site. We are not NTA.

Weightage: what the paper actually did

Kinetic Theory carried 1 question in the NEET 2026 paper. One paper is a data point, not a destiny: NTA moves weight between chapters every cycle, which is why the weightage tables deserve care. The stable facts are the paper's shape: 180 questions, 720 marks, +4 right, −1 wrong.

Sample PYQs from this chapter

Real questions NTA asked from Kinetic Theory, with the answer and the working. Try before you peek.

Question 1 · NEET 2026

A flask contains argon and chlorine in the ratio of 2 : 1 by mass. The temperature of the mixture is 27∘^{\circ}C. The ratio of root mean square speed of the molecules of the two gases (vrmsArvrmsCl)\left(\frac{v_{rms}^{Ar}}{v_{rms}^{Cl}}\right) is: (Atomic mass of argon = 40.0 u and molecular mass of chlorine = 70.0 u)
  1. A.72\frac{\sqrt{7}}{2}
  2. B.74\frac{7}{4}
  3. C.72\frac{7}{2}
  4. D.27\frac{2}{\sqrt{7}}
Answer and explanation

Answer: A

Since vrms=3RTMv_{rms} = \sqrt{\frac{3RT}{M}}, at the same temperature vrms∝1Mv_{rms} \propto \frac{1}{\sqrt{M}}. Therefore vrmsArvrmsCl=MClMAr=7040=72\frac{v_{rms}^{Ar}}{v_{rms}^{Cl}} = \sqrt{\frac{M_{Cl}}{M_{Ar}}} = \sqrt{\frac{70}{40}} = \frac{\sqrt{7}}{2}, option (1). The 2:1 mass ratio of the gases does not affect the rms speed, which depends only on temperature and molar mass.

How to practise Kinetic Theory

Chapter by chapter, against real past-paper questions, on a screen: NEET is computer based from 2027. Read the chapter once, then attempt its PYQs until your accuracy stops climbing, and let the wrong answers tell you which lines to reread. If the chapter keeps refusing to stick, that has its own guide. There is also a free 12-question mock on the exam screen.

Nearby Physics chapters

Questions

How many questions did Kinetic Theory have in NEET 2026?

Kinetic Theory carried 1 question in the NEET 2026 paper. Weightage shifts between cycles, so treat it as a probability, not a promise.

Where can I practise Kinetic Theory PYQs for NEET?

In the BrainIt app, free until the 2027 exam: its bank holds 50,000 past NTA questions tagged to all 83 chapters, including this one, with accuracy tracked per chapter. A sample question from this chapter is on this page.

Is Kinetic Theory important for NEET 2027?

It is part of the Physics syllabus the paper draws from, and NEET 2027 is computer based, so practise it on a screen. Your own accuracy in the chapter matters more than any weightage table: a heavy chapter you already score well on needs less time than a light one you keep missing.

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