Book Online Demo

Check Your IQ

Try Test

Courses

A concave spherical mirror produces $- \frac{1}{2}$ magnification when an object is placed at a distance of $50 cm$ from the mirror. Where the object should be placed to get the magnification of $- \frac{1}{5}$ ?

see full answer

21% of IItians & 23% of AIIMS delhi doctors are from Sri Chaitanya institute !!

An Intiative by Sri Chaitanya

125 cm

100 cm

324 cm

129 cm

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

The object should be placed at

125 cm

from the mirror to get the magnification of

- \frac{1}{5}

.
Given,
As the object is placed at a distance of

50 cm

from the mirror,

u = - 50 cm

m = - 1 / 2

Substituting these values in magnification formula, we get

m = - \frac{v}{u}

\Rightarrow - \frac{1}{2} = - \frac{v}{(- 50)}

\Rightarrow v = - 25 cm

Now, substituting the value of

v

in magnification formula for calculating the distance of the object when the magnification produced is

- \frac{1}{5}

, we get

m = - \frac{v}{u}

\Rightarrow - \frac{1}{5} = - \frac{(- 25)}{u}

\Rightarrow u = - 125 cm

Therefore, the object should be placed at a distance of

125 cm

from the mirror.

Watch 3-min video & get full concept clarity