Question

Light is made to travel from medium 1 to medium 3 through medium 2 as shown in figure. If ${\mu }_1,{\mu }_2$ and ${\mu }_3$ are the refractive indices of first, second and third media and $i_2>i_1$, then

• A. $sin{r}_1=sin{r}_2:sin{i}_1<sin{i}_2$
• B. ${}^1{\mu }_2{>}^2{\mu }_1{;}^2{\mu }_3{<}^3{\mu }_2$
• C. ${}^1{\mu }_3{<}^3{\mu }_1$
• D. All the above

Answer 1

The correct option is D All the above

(D)

$\to$ From figure, $r_1=r_2$ &

$i_1<i_2$

$\therefore$ $\sin r_1=\sin r_2\&\sin i_1>\sin i_2$

$\to$ Medium $2$ is denser compared to medium $1$.

$\therefore$ $1{\mu }_2>2{\mu }_1$

Medium $3$ is rarer compared to medium $2$

$\therefore$ $2{\mu }_3<3{\mu }_2$

$\to$ Since $i_1<i_2$ for $r_1=r_2$

Medium $3$ is rarer compared to medium $1$

$\therefore$ $1{\mu }_3<3{\mu }_1$