For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index

Options

A. lies between `sqrt(2)` and 1
B. lies between 2 and `sqrt(2)`
C. is less than 1
D. is greater than 2

Answer

B

Explanation

`mu=(sin((A+delta_(m))/(2)))/(sin A//2)=(sin ((A+A)/(2)))/(sinA//2)`
In given situation, value of `A` varies from 0 to `90^(@)`. So `mu_(min)=2cos((90^(@))/(2))=sqrt(2)`
and `mu_(max)=2cos0^(@)=2`