Question

An equilateral prism is lying on the prism table of a spectrometer in minimum deviation position. if the angle of incidence is ${60}^{\circ }$ then the angle of deviation will be:

• A. ${90}^{\circ }$
• B. ${60}^{\circ }$
• C. ${45}^{\circ }$
• D. ${30}^{\circ }$

Answer 1

The correct option is B ${60}^{\circ }$

Minimum deviation position is $i_i=i_e$
$\delta =i_i+i_e-A=60+60-60=60$.