Question

the focal length of a Convex lens is 50cm . If an object is kept at a distance of 75cm from the lens . Then find the image distance and magnification produced by lens​

Answer 1

The image distance v = 30cm and magnification will be 0.4.

Explanation:

To find the value of image distance

Given focal length f = 50cm

and object distance u = 75cm

then by using the formula to find the value of v, we have

$\frac{1}{f} = \frac{1}{v} - \frac{1}{u}$

$\frac{1}{v} = \frac{1}{f} + \frac{1}{u}$

$\frac{1}{v} = \frac{1}{50} + \frac{1}{75}$ now taking LCM

$\frac{1}{v} = \frac{(75 + 50)}{3750}$

$\frac{1}{v} = \frac{125}{3750}$, solve this, we find the value of v

then v = 30cm ( Image distance)

Now to find the value of magnifiaction produced by lens , we have

M.P( Magnification) = $\frac{Image-distance}{Object-distance} = \frac{v}{u}= \frac{30}{75} = 0.4cm$

Magnifiaction produced by lens will be 0.4cm