A concave mirror cannot be used as:

Which of the following mirror can form a real image of an object?

The mirror which can form a magnified image of an object is _____.

An object is placed at a distance of $15 \mathrm{cm}$ from a convex lens of focal length $10 \mathrm{cm}$. The image obtained on the screen is:

When an object is kept at any distance in front of a concave lens, the image formed is always:

The splitting up of white light into seven colours on passing through a glass prism is called:

A concave mirror has a focal length of $10 \mathrm{cm}$. At which of the following distance should an object be placed so that it may form a virtual, erect and magnified image?