Q138 · CSIR NET Chemistry, June 2011
Paper: CSIR NET June 2011 · Subject: Physical Chemistry · Chapter: Quantum Chemistry · Topic: Postulates Operators · Marks: 2 · Difficulty: Easy
A constant of motion is defined by the equation:
(a)$[\mathrm{H}, \mathrm{A}]=0$
(b)$\langle[\mathrm{H}, \mathrm{A}]\rangle=0$
(c)$\mathrm{A}=\mathrm{f}(\mathrm{H})$
(d)$\mathrm{A}^{\dagger}=\mathrm{A}$
Answer
Answer: A ✓ checked by 4AB · confidence high
The source book printed no answer; this one was worked out and checked — see the explanation.
Explanation
A is a constant of motion when it commutes with the Hamiltonian, [H, A] = 0 (a).
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