A ray of light is incident on an equilateral prism in such a way that the angle of incidence is equal to the angle of emergence and each is equal to 3/4 of the prism angle. The angle of deviation for the ray of light is
$45^{\circ}$
$30^{\circ}$
$39^{\circ}$
$20^{\circ}$

Question

A ray of light is incident on an equilateral prism in such a way that the angle of incidence is equal to the angle of emergence and each is equal to 3/4 of the prism angle. The angle of deviation for the ray of light is
$45^{\circ}$
$30^{\circ}$
$39^{\circ}$
$20^{\circ}$

Toppr Admin · Accepted Answer

As-xA0-angle of incidence is equal to the angle of emergence the prism is set in minimum deviation position-x3B4-min-ii-ie-x2212-A-34-60-60-x2212-60-30o-

A ray of light is incident on an equilateral prism in such a way that the angle of incidence is equal to the angle of emergence and each is equal to 3/4 of the prism angle. The angle of deviation for the ray of light is 45∘30∘39∘20∘

As angle of incidence is equal to the angle of emergence the prism is set in minimum deviation positionδmin=ii+ie−A=34(60+60)−60=30o.

A ray of light is incident on an equilateral prism in such a way that the angle of incidence is equal to the angle of emergence and each is equal to 3/4 of the prism angle. The angle of deviation for the ray of light is
$45^{\circ}$
$30^{\circ}$
$39^{\circ}$
$20^{\circ}$

As angle of incidence is equal to the angle of emergence the prism is set in minimum deviation position

$δ_{m i n} = i_{i} + i_{e} - A = \frac{3}{4} (60 + 60) - 60 = 30^{o}$ .