Question

when an object of height 3cm is placed at
a distance of 30 cm from a lens a real
Image is formed at distsnce of 60 cm .
find out the height of the image​

Answer 1

Explanation:

Given,

Radius of curvature, R=40cm

Object distance, u=30cm

Object height, h

o

=3cm

The focal length of the mirror=f=−

2

R

=−20cm

From mirror equation,

v

1

+

u

1

=

f

1

⟹

v

1

+

−30

1

=

−20

1

⟹v=−60cm

The magnification, M=

u

−v

=−

−30

−60

=−2

Hence the image is inverted, enlarged, real and its size is 2×3cm=6cm