Question

u=40 v=60 find F.
chapter name is
Reflection of light at curved surfaces...

Answer 1

Answer:

The answer is 24 i.e.f=24

Explanation:

We know that

1/f=1/v + 1/u

therefore

1/f = 1/60 + 1/40

1/f = (2+3)/120

1/f = 5/120

5f = 120

f = 24