Question

R.I of glass w. r. t air is 3/2, then the R.I of air w. r. t. glass is
(A) 3/4
(b) 2/3
(C) 1/3
(D) 3

Answer 1

Since we know about the principal of reversibility, i.e. a mew g = 1/ g mew a
2/3 is your answer....

Answer 2

R.I of air w. r. t. glass

=RI of air/RI of glass

=1/(3/2)

=2/3