Question

The distance at which object is placed in front of the convex lens of focal length 10cm to obtain a real image of double its size is7​

Answer 1

Explanation:

Convex lens gives the real and double-sized image when the object is placed exactly between the focus and radius of curvature.

We have,

f

1

=

v

1

−

u

1

m=

u

v

=2 or v=2u

∴

f

1

=

2u

1

−

−u

1

=

2u

1

+

u

1

=

2u

3

or

10

1

=

2u

3

or u=15cm