A point source of light ,S is placed at a distance L in front of the centre of plane mirror of width d which is a hanging vertically on wall ,A man walks in front of the mirror , at a distance 2L as shown below . The distance over which the man can see the image of the light source in the mirror is :

Options

A. d/2
B. d
C. 2d
D. 3d

Answer

D

Explanation

The ray diagram will be as follow :

`HI = AB = d, DS = CD = (d)/(2)`
Since, AH = 2AD ` therefore GH = 2CD = 2(d)/(2) = d`
Similarly, IJ =d
`therefore GJ = GH + HI +IJ = d + d + d = 3d`