$A$ man having height $6 \ m$ observes an erect image of height $2 \ m$. The mirror used is:

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......$cm$

An object placed in front of a concave mirror at a distance of $x \ cm$ from the pole gives a $3$ times magnified real image. If it is moved to a distance of $(x+5) \ cm$, the magnification of the image becomes $2$. The focal length of the mirror is: (in $cm$)

An object is placed at $20 \, cm$ from a convex mirror of focal length $10 \, cm$. The image formed by the mirror is

$A$ driver sitting inside a parked car is watching vehicles approaching from behind with the help of a side-view mirror,which is a convex mirror with a radius of curvature $R = 2 \ m$. Another car approaches from behind with a uniform speed of $90 \ km/h$. When the car is at a distance of $24 \ m$ from the mirror,the magnitude of the acceleration of the image in the side-view mirror is $a$. The value of $100a$ is $m/s^2$.

If an object is placed $10 \ cm$ in front of a concave mirror of focal length $20 \ cm,$ the image will be