Question

An object is placed at a distance of 15 cm from a convex lens with focal length 5 cm. a) What is image distance from this lens? Which side of the lens? b) What is nature of the image? What is its linear magnification?

Answer 1

ANSWER

Here point I would be center of curvature of the mirror.

So focal length of mirror f=

2

MI

​

For lens,

f

1

​

=

v

1

​

−

u

1

​

v

1

​

=

f

1

​

+

u

1

​

Here , f=+10cm,u=−15cm

v

1

​

=

10

1

​

+

−15

1

​

v=+30cm

MI=LI−LM

=30−10=20cm

f=

2

MI

​

=

2

20

​

f=10c