Draw ray diagrams showing the image formation by a concave mirror when an object is placed at infinity.

Draw ray diagram in each case to show the position and nature of the image formed when the object is placed at the centre of curvature of a concave mirror.

Draw ray diagram in each case to show the position and nature of the image formed when the object is placed between the pole P and focus F of a concave mirror.

Draw ray diagram in each case to show the position and nature of the image formed when the object is placed in front of a convex mirror.

Draw ray diagram in each case to show the position and nature of the image formed when the object is placed at $2\mathrm{F}$ of a convex lens.

Draw ray diagram in each case to show the position and nature of the image formed when the object is placed in front of a concave lens.

An object $3 \mathrm{cm}$ high produces a real image $4.5 \mathrm{cm}$ high, when placed at a distance of $20 \mathrm{cm}$ from a concave mirror. Calculate the position of the image.