Assertion :In He-Ne laser, population inversion takes place between energy levels of neon atoms. Reason: Helium atoms have a meta-stable energy level.

Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

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Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

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Assertion is correct but Reason is incorrect

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If Assertion is incorrect but Reason is correct

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Solution

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
In transition in He-Ne laser, an electric discharge in gas pumps the helium atom to higher energy states (which is metastable state $\approx 10^{- 8} s$ ). These He atoms collide with the ground state neon atoms and excite to higher states (levels) and produce in inverted population inversion causing a unidirectional photon beam (laser light).

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(c) Assertion is correct, but reason is incorrect
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