Question

The observer can see through distance ( mathrm{P}^{prime} mathrm{Q} ) ', where reflected ray from B can meet line.
[
begin{array}{l}
text { From geometry } C D=d=c^{prime} P^{prime}
qquad begin{aligned}
P^{prime} Q^{prime} &=C^{prime} D^{prime}+P^{prime} D^{prime}+Q^{prime} C^{prime}
&=d+2 P D+2 C Q
&=d+2(P D+q C)
&=d+2 d
&=3 d
end{aligned}
end{array}
]

# d) 10.2 cm s' 16. d) 20 CMS b) 20 72 cms! c) 40 cm s A point source of light B is placed at a distance L in front of the centre of a mirror of width d hung vertically on a wail. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it as shown in fig. The greatest distance over which he can see the image of the light source in the mirror is 17. c) 20 d) 3d a) d/2bb d

Solution