Question

3. At what distance from the face of a person, a
shaving mirror of focal length 15 cm should be
placed, so as to obtain an erect image of face 3
times magnified?


Plz give the correct answer.​

Answer 1

Focal length ,F = ?

object distance is = -20cm

Magnification ,1.5=

−20

−V

V=30cm

using the mirror formula

V

1

+

u

1

=

F

1

30

1

−

20

1

=

F

1

60

2−3

=

F

1

=F=−60cm

I hope you are understand my solution