Question

Two identical thin isosceles prism of refracting angle 'A' and refractive index $\mu$ are placed their bases touching each other. Two parallel rays of light are incident on this system as shown The distance of the point where the rays converge from the prism is:

• A. $\frac{h}{\mu A}$
• B. $\frac{h}{A}$
• C. $\frac{h}{(\mu -1)a}$
• D. $\frac{\mu h}{(\mu -1)a}$

Answer 1

The correct option is C $\frac{h}{(\mu -1)a}$

$\begin{array}{c}\text{since}\tan \delta =\frac{h}{f}\Rightarrow f=\frac{h}{\tan \delta }\\ \text{further,}\delta =(\mu -1)A\Rightarrow f=\frac{h}{(\mu -1)A}\\ \therefore f=\frac{h}{(\mu -1)A}\end{array}$