Day and night settings for rearview mirrors use:

Light incident normally on a plane mirror attached to a galvanometer coil retraces its path as shown in the figure. $A$ current in the coil produces a deflection of $3.5^{\circ}$ of the mirror. What is the displacement (in $cm$) of the reflected spot of light on a screen placed $1.5\; m$ away?

Light of wavelength $5000 \,\mathring{A}$ falls on a plane reflecting surface. What are the wavelength and frequency of the reflected light? For what angle of incidence is the reflected ray normal to the incident ray?

$A$ ray gets successively reflected from two mirrors inclined at an angle of $40^o$. If the angle of incidence on the first mirror is $30^o$,then the net deviation of this ray after two reflections is: (in $^o$)

Two parallel mirrors $M_1$ and $M_2$ are separated by a distance $a$. An object is placed between them. What is the distance between the $n^{th}$ image formed by $M_1$ and the $n^{th}$ image formed by $M_2$?

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