For refraction through a small angled prism, the angle of minimum deviation

Options

A. increases with increase in refractive index of a prism
B. will be `2delta` for a ray of refractive index `2.4` if it is delta for a ray of refractive index `1.2`
C. is directly proportional to the angle of the prism
D. will decrease with increase in refractive index of the prism

Answer

A

Explanation

`mu=(sin(A+delta_m)/2)/sin(A/2),`
For small angled prism, `sinA/2~~A/2`
`:. mu=sin(A+delta_m)/2=(muA)/2`
With increase in mu, (sin(A+delta_m)/2) will increase
Hence, `delta_m` will increse.