Define the following terms:
$(i)$ Angle of incidence
$(ii)$ Angle of reflection
$(iii)$ Plane of incidence

Which of the following is a part of a spherical mirror?

The magnification of a real image formed by a concave mirror is always ...

In a diagram,show the following for both a convex mirror and a concave mirror:
$(i)$ Principal axis
$(ii)$ Pole
$(iii)$ Focus
$(iv)$ Centre of curvature
$(v)$ Radius of curvature

$A$ ray of light $XY$ is incident on a mirror as shown in the figure. The angle of incidence for this ray is the angle between it and the line joining two other points in the figure. Name these two points and show the course of rays after reflection.

$(a)$ Draw a ray diagram in each of the following cases to show the position and nature of the image formed when the object is placed:
$(i)$ between optical centre and principal focus $(F)$ of a convex lens.
$(ii)$ between $F$ and $2F$ of a convex lens.
$(iii)$ at $2F$ of a convex lens.
$(b)$ How will the nature and position of the image formed change in case $(i)$ and $(ii)$ in part $(a)$ of this question if the lens is replaced by a concave lens? Draw the corresponding ray diagram.