Question

In the diagram a rat is passing through a broken prism,find angular deviation for the ray:

• A. ${105}^0$
• B. ${30}^0$
• C. ${60}^0$
• D. ${15}^0$

Answer 1

The correct option is D ${15}^0$

Reconstructing the broken prism we have

By sum of angles of prism

${180}^o=A+{30}^o+{60}^o\Rightarrow A={90}^o$

then, deviation will be

$\delta =i_1+i_2-A$

$\delta ={45}^{\circ }+{60}^{\circ }-{90}^{\circ }$

$\delta ={15}^{\circ }$