The focal length of a convex mirror is $20\, cm$. Its radius of curvature will be.....$cm$.

All of the following statements are correct except (for a real object):

While using an electric bulb for street lighting, the reflector should be a:

In a car,a rear-view mirror having a radius of curvature $1.50 \, m$ forms a virtual image of a bus located $10.0 \, m$ from the mirror. The factor by which the mirror magnifies the size of the bus is close to

The image formed by a convex mirror of focal length $30 \ cm$ is a quarter of the size of the object. The distance of the object from the mirror is......$cm$

$A$ linear object of height $10 \text{ cm}$ is kept in front of a concave mirror of radius of curvature $15 \text{ cm}$,at a distance of $10 \text{ cm}$. The image formed is