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The de-Broglie wavelength of neutron in thermal equilibrium at temperature T is:

1. 30.8/√T Å
2. 3.08/√T Å
3. 0.308/√T Å
4. 0.0308/√T Å

Correct answer: 3.08/√T Å

Solution

The de-Broglie wavelength is given by λ = h / √(2mEk), where Ek = (3/2)kBT for a particle in thermal equilibrium. Substituting constants and simplifying gives λ proportional to 1/√T, leading to the correct numerical factor in option B.

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