Question

Identify the prism formula from the following.

(a) μ=⁡\(\frac {sin [ \frac {A – \delta_m}{2} ] }{ sin⁡(\frac {A}{2}) } \)

(b) μ=⁡\(\frac {sin [ \frac {A + \delta_m}{4} ] }{ sin⁡(\frac {A}{2}) } \)

(c) μ=⁡\(\frac {sin [ \frac {A + \delta_m}{2} ] }{ sin⁡(\frac {A}{2}) } \)

(d) μ=⁡\(\frac {sin [ \frac {A + \delta_m}{2} ] }{ cos⁡(\frac {A}{2}) } \)

I have been asked this question in a job interview.

This is a very interesting question from Ray Optics topic in section Ray Optics and Optical Instruments of Physics – Class 12

Answer 1

Right choice is (c) μ=⁡\(\frac {sin [ \frac {A + \delta_m}{2} ] }{ sin⁡(\frac {A}{2}) } \)

For explanation I would say: The refractive index of the material of the prism is given as:

 μ=⁡\(\frac {sin [ \frac {A + \delta_m}{2} ] }{ sin⁡(\frac {A}{2}) } \)

Where A ➔  Angle of the prism and δm ➔  angle of minimum deviation. This is known as the prism formula.