Question

Calculate the position of an image of an object placed 30
cm away from a concave lens focal length15 cm. Also calculate
the magnifying power of the lens.
​

Answer 1

Answer:

here

u = -30cm

f = -15cm

by seeing the question we find that object is placed at centre of curvature..

and the c = 2f = -30cm

so we conclude that object is formed on centre of curvature but another side of the lens..

so v = 30cm

magnification = v/u = -30/30 = -1

hope this will help you

Answer 2

Answer:

v= 30 , m= -1

Explanation:

Given that ,

u = -30 cm

f = 15 cm

v = ?

m = ?

1/f = 1/v -1/u

1/15 = 1/v+1/30

1/v = 1/15 - 1/30

1/v = 2-1/30

1)v =1/30

v=30 cm

and

m=v/u

m= -30/30

m = -1cm