Optics Ques 23
- A point source of light $S$, placed at a distance $L$ in front of the centre of a plane mirror of width $d$, hangs vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror at a distance $2$ $ L$ from it as shown. The greatest distance over which he can see the image of the light source in the mirror is
$(2000,2 M)$
(a) $d / 2$
(b) $d$
(c) $2 $ $d$
(d) $3 $ $d$
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Answer:
Correct Answer: 23.(d)
Solution:
Formula:
Characteristics of image due to Reflection by a Plane Mirror:
- The ray diagram will be as follows :
Since, $A H=2 A D$
$ \therefore \quad G H=2 C D=2 \frac{d}{2}=d $
Similarly,
$ \begin{aligned} I J & =d \\ G J & =G H+H I+I J \\ & =d+d+d=3 d \end{aligned} $
BETA
