Question

A plane mirror makes an angle of 30 degrees with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and the reflected ray ?

Answer 1

answer is 60degree bcoz the plane makes an angle of 30' with horizontal          

and the incident ray act as normal.

Answer 2

Angle between mirror and ray reflected is  $\bold{60^{\circ}}$.

Solution:

The plane mirror making an angle of $30^{\circ}$ with the normal and on striking the mirror vertical the reflected ray angle is calculated as follows,

Given: Angle of mirror with horizontal = $30^{\circ}$. So the incident ray will be normal, i.e., perpendicular to the mirror

The angle of incidence striking vertical will be actually at an angle with the horizontal at $=90^{\circ}-30^{\circ}=60^{\circ}$

Angle of incidence = Angle of reflection.  

Angle of reflection with the horizontal becomes $60^{\circ}$.

Angle between mirror and reflected ray $=90^{\circ}-30^{\circ}=60^{\circ}$