Question

a concave mirror of focal length 10cm is placed at a distance of 35cm from the wall how far from the wall an object be placed so that its image formed by the mirror falls on the wall

Answer 1

Hey friend!!


Here's ur answer....

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Focal length = - 10 cm
Image distance (v) = 35 cm

Using mirror formula :

$\frac{1}{f} = \frac{1}{v} + \frac{1}{u} \\ - \frac{1}{10} = \frac{1}{35} + \frac{1}{u} \\ \frac{1}{u} = - \frac{1}{10 } - \frac{1}{35} \\ \frac{1}{u} = \frac{ - 7 - 2}{70} \\ u = \frac{ - 70}{9} \\ u = - 7.77cm \: (approx)$

So, object distance = 7.77 cm.


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Hope my calculations are correct..


Thank you :) :)))