Question

A concave lens is of focal length 30 cm. Calculate at what distance should an object be placed from the lens so that it forms an image at 60 CM on the other side of the lens? Find the magnification produced by the lens in this case.

Answer 1

put ur question,in this formula.
1/f=1/v-1/u.where v is final ray and u is initial ray...hope it help u,give thanks..

Answer 2

F = -(30)
v =-(60)

u= ?

1/f = 1/v -1/u
1/-30 = 1/-60 -1/u
1/u = 1/-(60) + 1/30
= -1 + 2 / 60

= 1/60
U = 60cm

m = V/ U
= 60 / -60
= - 1