Light incident on a surface separating two media is partly reflected and party refracted as shown in Fig. Then :
.

Options

A. `sini=(mu_(2))/((mu_(1)^(2)+mu_(2)^(2))^(1/2))`
B. `tani=(mu_(1))/(mu_(2))`
C. `sini=tanr`
D. `sini=secr`

Answer

A

Explanation

Here `i=90^(@)-r`, so `sini=sin(90^(@)-r)=cosr`
Also, `(mu_(2))/(mu_(1))=(sini)/(sinr)=(sini)/(sqrt(1-cos^(2)r))=(sini)/(sqrt(1-sin^(2)i))`
or `mu_(1)^(2)sin^(2)i=mu_(2)^(2)-mu_(2)^(2)sin^(2)i`
or `(mu_(1)^(2)+mu_(2)^(2))sin^(2)i=mu_(2)^(2)` or `sini=(mu_(2))/(sqrt(mu_(1)^(2)+mu_(2)^(2)))*`