Physics

Problem

For two structures, namely

S_1

with

n_1 = \sqrt{45}/4

and

n_2 = 3/2

, and

S_2

with

n_1 = 8/5

and

n_2 = 7/5

, taking the refractive index of water to be

4/3

and that of air to be 1, which option(s) is(are) correct? a. NA of

S_1

immersed in water is the same as that of

S_2

immersed in a liquid of refractive index

\frac{16}{3\sqrt{15}}

b. NA of

S_1

immersed in liquid of refractive index

\frac{6}{\sqrt{15}}

is the same as that of

S_2

immersed in water c. NA of

S_1

placed in air is the same as that of

S_2

immersed in liquid of refractive index

\frac{4}{\sqrt{15}}

d. NA of

S_1

placed in air is the same as that of

S_2

placed in water