Question

A divergent lens has a focal length of 20cm.
At what distance should an object be placed
so that the image is formed 10 cm away from
the lens. What is the magnification produced
by the lens?
​

Answer 1

Answer:

DIVERGENT LENS: CONCAVE LENS-

f=-20cm

v=-10cm because a concave lens always forms a virtual image on the same side as the object.  

ho=4cm

1/f = 1/v -  1/u [ Lens Formula]  

-1/20 = - 1/u - 1/10

-1/u = 1/10 -  1/20

-1/u = (2-1)/20

-1/u  = 1/20

u= - 20 cm

m = v/u = hi/ho

1/2 = hi/4

hi = 2cm

Explanation: