$A$ man runs towards a plane mirror at a speed of $15 \, m/s$. The speed of the image relative to the mirror is ...... $m/s$.

Light rays fall on a plane mirror and form a real image. Therefore,the incident rays are:

It is desired to photograph the image of an object placed at a distance of $3\;m$ from a plane mirror. The camera,which is at a distance of $4.5\;m$ from the mirror,should be focused for a distance of......$m$.

$A$ thick plane mirror shows a number of images of the filament of an electric bulb. Of these,the brightest image is the

$A$ point source of light $S$ is placed at a distance $10\,cm$ in front of the centre of a mirror of width $20\,cm$ suspended vertically on a wall. $A$ man walks with a speed $10\,cm/s$ in front of the mirror along a line parallel to the mirror at a distance $20\,cm$ from it as shown in the figure. Find the maximum time during which he can see the image of the source $S$ in the mirror. (in $,s$)

$A$ light ray makes an angle of $10^o$ with the horizontal. It strikes a plane mirror inclined at an angle $\theta$ to the horizontal,and the reflected ray becomes vertical. What is the value of the angle $\theta$ in degrees?