An object is placed at a distance of $20 \ cm$ from the pole of a concave mirror of focal length $10 \ cm$. The distance of the image formed is

An object is placed beyond the centre of curvature $C$ of a concave mirror. If the distance of the object is $d_{1}$ from $C$ and the distance of the image formed is $d_{2}$ from $C$,the radius of curvature of this mirror is

An infinitely long rod lies along the axis of a concave mirror of focal length $f$. The nearer end of the rod is at a distance $u$ $(u > f)$ from the mirror. Its image will have a length:

In an experiment to determine the focal length $(f)$ of a concave mirror by the parallax method,a student places the object pin $\text{A}$ on the principal axis at a distance $x$ from the pole $\text{P}$. The student looks at the pin and its inverted image from a distance,keeping his/her eye in line with $\text{PA}$. When the student shifts his/her eye towards the left,the image appears to the right of the pin. Then:

An object of height $5 \, cm$ is placed at a distance of $1 \, m$ from a concave mirror of radius of curvature $20 \, cm$. What will be the height of the image in $cm$?

$A$ small rod of length $2 \, mm$ lies along the principal axis at a distance of $30 \, cm$ from a concave mirror of focal length $20 \, cm$. The axial length of the image of the rod is.....$mm$.