Question

Determine how far an object must be placed in front of a converging lens of focal length 15 cm in order to produce an erect (upright) image of linear magnification 4.

Answer 1

Answer:

The distance where the object must be placed in front of a converging lens is 11.25 cm

Explanation:

According to the problem the focal length, l= 15cm

and magnification,m is 4

Let the distance the object must be placed: d

As we know the magnification formula:

m= u/d

4= u/d

u= 4d

Now according to the lens formula:

1/u - 1/d= 1/l

=> 1/4d - 1/d= 1/15

=> d= -11.25