Question

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

• A. Both assertion and reason are true and reason is the correct explanation of assertion
• B. Both assertion and reason are true but reason is not the correct explanation of assertion
• C. Assertion is true but reason is false.
• D. Both assertion and reason are false.

Answer 1

Answer: (B)

The transition in He-Ne Laser is shown below.

An electric discharge is the gas pump the helium atom to higher energy states. These He atoms collide with the ground state atoms and excite to higher states and produce population inversion causing a directional photon beam.