The image formed by a converging lens of focal length is of a distance of 2f from the lens. Calculate the lateral magnification produced

A.

0.5

B.

1

C.

1.5

D.

2

E.

3

Correct answer is B

Using the lens formula,

\(\frac{1}{v} + \frac{1}{u} = \frac{1}{f}\)

Where u, v and f are the object distance, image distance and focal length respectively.

\(\therefore \frac{1}{2f} + \frac{1}{u} = \frac{1}{f}\)

\(\frac{1}{u} = \frac{1}{2f} - \frac{1}{f} \implies \frac{1}{u} = \frac{1}{2f}\)

\(u = 2f\)

\(\therefore Magnification = \frac{\text{image distance}}{\text{object distance}}\)

= \(\frac{2f}{2f}\)

= 1