Question

Alena of focal length 5 cm is being used by a student in the laboratory as a magnifying glass. His least distansd of distinct vision is 25cm. What magnification Is the student getting.

Answer 1

It is a magnifying glass hence the lens used is convex
Now,
f = 5cm, u = -25cm, v = ?, m = ?
Using the formula
1/v - 1/u = 1/f,
we get
v = 25/4
Now, as u know
m = v/u,
so putting the value of v & u in this,
we get m = -0.25