JEE PYQ: Ray Optics Question 29
Question 29 - 2020 (08 Jan Shift 2)
An object is gradually moving away from the focal point of a concave mirror along the axis of the mirror. The graphical representation of the magnitude of linear magnification ($m$) versus distance of the object from the mirror ($x$) is correctly given by
(1) [Graph 1]
(2) [Graph 2]
(3) [Graph 3]
(4) [Graph 4]
Show Answer
Answer: (3)
Solution
Using mirror formula, magnification is given by $m = \frac{f}{u - f} = \frac{-1}{1 - \frac{u}{f}}$ At focus magnification is $\infty$ And at $u = 2f$, magnification is 1. Hence graph (4) correctly depicts ‘$m$’ versus distance of object ‘$x$’ graph.
BETA
