The distance between the object kept at $2 \, m$ from a plane mirror and its image is $.....$ (in $, m$)

What is the radius of curvature of a plane mirror?

Draw a labelled ray diagram to locate the image of an object formed by a convex lens of focal length $20 \, cm$ when the object is placed $30 \, cm$ away from the lens.

You are given water,mustard oil,glycerine,and kerosene. In which of these media would a ray of light incident obliquely at the same angle bend the most?

One half of a convex lens of focal length $10\, cm$ is covered with a black paper. Can such a lens produce an image of a complete object placed at a distance of $30\, cm$ from the lens? Draw a ray diagram to justify your answer.
$A$ $4\, cm$ tall object is placed perpendicular to the principal axis of a convex lens of focal length $20\, cm$. The distance of the object from the lens is $15\, cm$. Find the nature,position and size of the image.

If an object of $4 \, cm$ height is placed at a distance of $12 \, cm$ from a concave mirror,then its image is formed at a distance of $24 \, cm$ from the mirror and behind it. What will be the height of the image (in $, cm$)?