Question

The figure shows the graph of deviation ${}^{\prime }{\delta }^{\prime }$ versus angle of incidence $\varphi$ for a light ray striking a prism. Angle of prism is :

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

Answer 1

Answer: (B)

${45}^{\circ }$

By comparing graph with standard plot, we get $\delta =30°,i_1=15°,i_2=60°$

as $\delta =i_1+i_2-A\therefore A=i_1+i_2-\delta =15°+60°-30°=45°$