KTUYSBeta
Log inSign up

Cheat sheet · Class 11 · CBSE · Science Physics

Kinetic Theory cheat sheet

The whole chapter on one page: key formulas, facts and the points to remember, for quick revision before a test.

CBSE Class 11 · Physics

Cheat sheet

Chapter 12Kinetic Theory

Each degree of freedom gets ½kT of energy.

1. Gas Laws

PV=μRT=NkBTPV = \mu RT = Nk_BT
  • Boyle: PV const (T fixed).
  • Charles: V ∝ T (P fixed).
  • Avogadro: equal volumes hold equal molecules at same T, P.
  • Dalton: P = P₁ + P₂ + …

2. Pressure & Speeds

P=13ρ v2‾P = \tfrac13 \rho\,\overline{v^2}
vrms=3RTMv_{rms} = \sqrt{\dfrac{3RT}{M}}
KEavg=32kBTKE_{avg} = \tfrac32 k_BT per molecule

3. Equipartition of Energy

GasDegrees of freedomCvγ = Cp/Cv
Monatomic332R\tfrac32 R5/3
Diatomic (rigid)552R\tfrac52 R7/5
Polyatomic (non-linear)63R3R4/3

4. Mean Free Path

l=12 nπd2l = \dfrac{1}{\sqrt2\,n\pi d^2}

n = number density, d = molecular diameter.

5. Key Points

  • Real gases behave ideally at low P, high T.
  • v_rms ∝ √T and ∝ 1/√M.
  • k_B = R/N_A = 1.38 × 10⁻²³ J/K.
  • Temperature measures average KE.

Remember: PV = μRT | v_rms = √(3RT/M) | ½kT per degree of freedom

Kinetic Theory: questions and notes

More Class 11 · CBSE · Science Physics cheat sheets

Practise Kinetic Theory

Sign up free to practise the full chapter. Questions you get wrong come back until you've mastered them.

Start practising free

Free to start · No credit card needed