Question

In Stimulated Absorption, what is the lifetime of atoms ground state?

(a) 1 second

(b) 1 minute

(c) 1 hour

(d) Infinity

This question was addressed to me in an internship interview.

Asked question is from Interaction of External Energy with the Atomic Energy States in section Laser of Engineering Physics II

Answer 1

Correct choice is (d) Infinity

Easy explanation: At the ground state, the atoms are perfectly stable. They are under no excessive force that might lead to become unstable. All the forces are balanced. Thus, as the atom is stable in ground state, it’s lifetime is infinity.