Question

A convex lens of focal length 10 cm is placed at a distance of 12 cm from a wall. How far from the lens should a object be placed so as to form it's real image on the wall?
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Answer 1

Answer:

ANSWER

f=10cm,v=12cm,u=?

We know,

f

1

=

v

1

+

u

1

10

1

=

12

1

−

u

1

u=−60cm

∴The object must be placed at a distance 60cm in front of the lens.