Question

an equilateral prism is made of glass of unknown refractive index.when a parallel beam of light is incident on a face of the prism the angle of minimum deviation is found to be 40°.calculate the refractive index of the material of prism.if the prism is placed in water of refractive index 1.33 ,find the new angle of minimum deviation of a parallel beam of light. (A*18)​

Answer 1

Answer:

The answer is 60°

Explanation:

Refractive index of a prism is given by the eq uation.

Refractive index   = [Sin{A+DM}/2]/SinA/2

= Sin[{60+Dm}/2]/Sin(60/2)=√3

= Sin{30+(Dm/2)}/Sin30=√3

= Sin{30+(Dm/2)}×2=√3

= 30+(Dm/2)= Sin-1(√3/2)=60°= Dm/2 = 60°–30

Dm =30×2=60°