Question

A light ray is made to incident on a glass plate with angle of incident 15 and then reflected. then the angle of defviation is

Answer 1

Answer:

150°

Explanation:

180°-2i

180°-30°

150°

Answer 2

The angle of deviation is 150°.

Given:

• The angle of incidence on the glass plate is 15°.

To find:

• Angle of deviation ?

Calculation:

• The angle of deviation refers to the angle by which the reflected ray deviates from the actual trajectory of the incident ray.

Refer to the diagram first .

As per law of reflection, angle of incidence will be equal to angle of reflection.

$\therefore \angle i = \angle r = {15}^{ \circ}$

Now, from the diagram we can say :

• Let angle of deviation be $\delta$.

$\implies \delta = {180}^{ \circ} - (\angle i + \angle r)$

$\implies \delta = {180}^{ \circ} - ( {15}^{ \circ} + {15}^{ \circ} )$

$\implies \delta = {180}^{ \circ} - {30}^{ \circ}$

$\implies \delta = {150}^{ \circ}$

So, angle of deviation is 150°.