Digital movie projectors work on the principle of

$A$ point source is placed at coordinates $(0,1)$ in the $xy$-plane. $A$ ray of light from the source is reflected on a plane mirror placed along the $X$-axis and perpendicular to the $xy$-plane. The reflected ray passes through the point $(3,3)$. What is the path length of the ray from $(0,1)$ to $(3,3)$?

When a plane mirror is placed horizontally on a level ground at a distance of $60 \ m$ from the foot of a tower,the top of the tower and its image in the mirror subtend an angle of $90^\circ$ at the eye. The height of the tower will be.....$m$.

Which of the following sets of letters does not show lateral inversion?

$A$ man moves towards a plane mirror with a velocity $v$ in a direction making an angle $\theta$ with the normal to the mirror. The magnitude of the velocity of the image relative to the man is:

$A$ light ray is incident perpendicular to the plane of a mirror. The angle of reflection will be ......$^o$.