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UPSC Civil Services (Mains)

Chemistry optional

  • 2 papers
  • 250 marks each
  • 3 h per paper
  • 5 of 8 questions, Q1 and Q5 compulsory

Paper I covers physical and inorganic chemistry.

UPSC Civil Services (Mains), Chemistry optional · 2024 · Paper I

Q2(a). Uncertainty principle; orthogonality of ψ₁ and ψ₂ in a box

Question

State Heisenberg's uncertainty principle. Show that for a particle in a one-dimensional box having length from 0 to L, the two normalised eigenfunctions corresponding to the eigenvalues E₁ and E₂ (characterised by quantum numbers 1 and 2 respectively) are orthogonal to each other.

Answer in brief

Δx Δpₓ ≥ h/4π; and ∫₀ᴸ ψ₁ψ₂ dx = 0, so ψ₁ and ψ₂ are orthogonal.

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CoversHeisenberg uncertainty principleparticle in a boxorthogonalityeigenfunctionszero-point energy

All parts of Question 2