If a parallel beam of light is incident on spherical mirrors, then after reflection, they pass through the focal point. If $F$ is the focal length and $R$ is the radius of curvature of the mirror, then:

What will be the height of the image when an object of height $2 \ mm$ is placed on the principal axis of a convex mirror (of radius of curvature $40 \ cm$) at a distance of $20 \ cm$ from the mirror?

The circular boundary of the concave mirror subtends a cone of half-angle $\theta$ at its centre of curvature. The minimum value of $\theta$ for which a ray incident on this mirror parallel to the principal axis suffers more than one reflection is......$^o$

$A$ diminished virtual image can be formed only in

$A$ 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

An object is placed at the principal focus of a convex mirror. The image will be at