Question

The number of atoms in the lower and upper energy states of a material are N1 and N2 respectively. For population inversion between
energy states of a material are N, and N2
these two levels
(A) N2 <N1
(C) N2 = N
(B) N2 = 0
(D) N2 > N​

Answer 1

Answer: n2<n1

Explanation:

Answer 2

Answer:

The correct option for this question is (A) N2 <N1.

Explanation:

What is population inversion?

In physics, population inversion is the redistribution of atomic energy levels within a system that takes place to enable laser activity. A system of atoms typically has an equilibrium temperature and always has more atoms in low energy states than in higher ones. The number of atoms in the higher energy state is higher than the number of atoms in the lower energy state under the population inversion condition. This is why it is referred to as an "inversion" in many well-known and frequently encountered physical systems.

Thus, when a system is in a state where more components are in higher, excited energy states than in lower, unexcited energy states, this is known as a population inversion.