Question

the focal length of a concave mirror is 10cm where should an object be placed so as to get its real image magnified 4 times ghd-zeoy-pwz

Answer 1

Explanation:

m=

O

I

=

u

−v

=±2

Case-1

u=2v

u

1

+

v

1

=

f

1

u

1

+

2u

1

=

10

−1

∴u=−15cm

case-2

u=−2v

u

1

−

2u

1

=

10

−1

⇒

2u

2−1

=

10

−1

∴u=−5cm

∴u=−5 or −15.