If the magnification $m$ of an image formed by a spherical mirror is negative,what is the nature of the image?

When an object is placed beyond the center of curvature $(C)$ in front of a concave mirror,where is the image formed and what is its nature?

The focal length of a plane mirror is $.....$

An object of height $5 \, cm$ is placed perpendicular to the principal axis of a concave lens of focal length $10 \, cm$. If the distance of the object from the optical centre of the lens is $20 \, cm$,determine the position,nature,and size of the image formed using the lens formula.

What is the centre of a curved mirror called?

Name the spherical mirror used as:
$(a)$ $1.$ Shaving mirror,
$2.$ Rear-view mirror in vehicles,
$3.$ Reflector in searchlights.
$(b)$ Write any three differences between a real and virtual image.