Question

In a thin prism of glass (refractive index 1.5), which of the following relations between the angle of minimum deviations {{\delta }_{m}}
and angle of refraction r
will be correct [MP PMT 1990]
A) {{\delta }_{m}}=r B) {{\delta }_{m}}=1.5\,r C) {{\delta }_{m}}=2r D) {{\delta }_{m}}=\frac{r}{2}

Answer 1

HEYA--------

dm = (-1)* 2r = (1.5-1)*2rdm = 0.5* 2r = rHence option A is correct.


TYSM...............@KUNDAN

Answer 2

The correct option for the relation is - A) delta =r

Angle of minimum deviation or delta is given by the mathematical equation mentioned as follows -

Delta = (u-1)A. Here, u represents refractive index.

Angle of refraction represented by r, is half the angle of prism at minimum deviation. This can be represented in equation as follows -

r = A/2

Now, keeping the values in equations -

Delta = (u-1)A

Delta = (u-1)2r

Delta = (1.5-1)2r

Delta = 3r-2r

Delta = r

Hence, angle of minimum deviation will be equal to angle of refraction.