JEE Main & Advanced
Physics
Ray Optics
Question Bank
Critical Thinking
question_answer
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 wall. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it as shown. The greatest distance over which he can see the image of the light source in the mirror is [IIT-JEE (Screening) 2000]
A) d/2
B) d
C) 2d
D) 3d
Correct Answer:
D
Solution :
According to the following ray diagram \[HI=AB=d\] and \[DS=CD=\frac{d}{2}\] \[\because \,AH=2AD\]\[\Rightarrow \,\,GH=2CD=\frac{2d}{2}=d\] Similarly\[IJ=d\]so \[GJ=GH+HI+IJ\]\[=d+d+d=3d\]