Question

An object placed 60 cm away from a lens a real is obtained 30 cm away from the lens.
what is the focal length ?​​

Answer 1

Here is ur answer

=>Convex lens will always produce a real image

u=-60cm

v=30cm

f=?

Lens formula :1/v+1/u=1/f

=>u+v/vu=1/f

=>vu/u+v=f

Now substitute the values.

30×-60/-60+30=f

-1800/-30=60

=>F=60cm

Hope it helps u