Question

A light ray is incident upon a prism in minimum deviation position and suffers a deviation of $34^{\circ}$. If the shaded half of the prism is knocked off, the ray will

• A. Suffer a deviation of $34^{\circ}$
• B. Suffer a deviation of $68^{\circ}$
• C. Suffer a deviation of $17^{\circ}$
• D. Not come out of the prism

Answer 1

Answer: (C)

By formula $\delta=(n-1) A $
$\Rightarrow 34=(n-1) A$ and in the second position $\delta^{\prime}=(n-1) \frac{A}{2}$
$\therefore \frac{34}{\delta'}=\frac{(n-1) A}{(n-1) \frac{A}{2}}$ or $\delta'=\frac{34}{2}=17^{\circ}$