$A$ small plane mirror is placed at the centre of a spherical screen of radius $R$. $A$ beam of light is falling on the mirror. If the mirror makes $n$ revolutions per second,the speed of the reflected light spot on the screen will be:

The separation between the screen and a plane mirror is $2r$. An isotropic point source of light is placed exactly midway between the mirror and the screen. Assume that the mirror reflects $100\%$ of the incident light. Then the ratio of illuminances on the screen with and without the mirror is

$A$ man runs towards a plane mirror at a speed of $15 \ m/s$. What is the speed of his image relative to the mirror? (in $m/s$)

Each of these diagrams is supposed to show two different rays being reflected from the same point on the same plane mirror. Which one of the following is correct?

$A$ long horizontal mirror is next to a vertical screen (see figure). Parallel light rays are falling on the mirror at an angle $\alpha$ from the vertical. If a vertical object of height $h$ is kept on the mirror at a distance $d$ from the screen,where $d > h \tan \alpha$,the length of the shadow of the object on the screen would be

$A$ boy of height $1.5\,m$ with his eye level at $1.4\,m$ stands before a plane mirror of length $0.75\,m$ fixed on the wall. The height of the lower edge of the mirror above the floor is $0.8\,m$. Which of the following is true?