An object 10 cm high is placed in front of a convex mirror of focal length 20 cm and the object is 30 cm from the mirror. Find the height of the image.(Ans:12cm)​

Correct option is

B

3

20

cm

Given; Focal length, f=20cm

Object distance, u=−10cm

Using mirror formula.

v

1

+

u

1

=

f

1

v

1

=

f

1

−

u

1

=

20

1

−

−10

1

(∵u=−10)

=

20

1

+

10

1

=

20

3

⇒v=

3

20

cm

the most reliable source of information.is wikipedia

i think it's 35 meters