Question

Figure shows the graph of angle of deviation $\delta$ versus angle of incidence $i$ for a light ray striking a prism. The prism angle is

• A. ${30}^{\circ }$
• B. ${45}^{\circ }$
• C. ${60}^{\circ }$
• D. ${75}^{\circ }$

Answer 1

Answer: (A)

${30}^{\circ }$

$\delta =e+i-A$
${30}^{\circ }={15}^{\circ }+{60}^{\circ }-A$
$\Rightarrow A={45}^{\circ }$.