A ray of light passing through the centre of curvature of a spherical mirror, after reflection:

1. passes through the focus
2. passes through the pole
3. becomes parallel to the principal axis
4. retraces its own path

If the radius of curvature of a concave mirror is 20 cm, its focal length is:

1. 10 cm
2. 20 cm
3. 40 cm
4. 80 cm

The image formed by a concave mirror is of the same size as the object, if the object is placed:

1. at the focus
2. between the pole and the focus
3. between the focus and the centre of curvature
4. at the centre of curvature

A convex mirror is used:

1. as a shaving mirror
2. as a head mirror by a dentist
3. as a rear view mirror by a driver
4. as a reflector in torch