Question

Critical angle for light going from medium (i) to (ii) is $\theta$. The speed of light in medium (i) is v, then the speed of light in medium (ii) is

• A. $v(1-\cos \theta )$
• B. $\frac{v}{\sin \theta }$
• C. $\frac{v}{\cos \theta }$
• D. $\frac{v}{(1-\sin \theta )}$

Answer 1

The correct option is B $\frac{v}{\sin \theta }$

Critical angle$=\theta$

Speed of light in medium(i)$=$v

$\sin \theta =\frac{1}{\mu }$

$\mu =\frac{1}{\sin \theta }$

$\frac{{\mu }_2}{{\mu }_1}=\frac{v_2}{v_1}$

where, ${\mu }_2=\mu$, ${\mu }_1=1$, $v_1=v$

$\Rightarrow \frac{\mu }{1}=\frac{v_2}{v}$

$\Rightarrow \frac{v_2}{v_1}=\frac{1}{\sin \theta }$

$\Rightarrow v_2=\frac{v}{\sin \theta }$