VKC ScienceChemistry for written exams Telegram

UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper II covers physical chemistry.

UPSC Combined Geo-Scientist, Mains · 2020 · Mains Paper II

Q8. Momentum expectation in a centred box

Question

Evaluate ⟨ p⟩ and ⟨ p²⟩ for a particle confined to -a/2<x<a/2 in a one-dimensional box.

Answer in brief

For the nth stationary energy eigenstate, ⟨ p⟩=0 and ⟨ p²⟩=n²π²ħ²/a².

Part of VKC Basic

Read the key points and the full model answer with VKC Basic

VKC Basic (₹999 for 6 months) opens every solved answer, the notes, the handbook and the daily answer archive. Every Mains test series includes it.

See what is included Already a member? Sign in

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

The handwritten model answer pages open with the VKC plan.
Read the whole 2020 solution2020 question paper

CoversMomentum expectation in a centred boxQuantum mechanics