Question

An object is placed at a distance of 60cm from a convex mirror where the magnification produced is 1/2 cm . where should be object placed to get a magnification 1/3

Answer 1

Answer:

Given:

u=-60cm

m=1/2

m=-v/u

1/2=-v/-60

-v=-30cm

v=30cm

f=?

by mirror formula:

-1/60+1/30=1/f

on solving:

f=60cm

m=1/3

1/3=-v/u

v=(1/3)u

f=60cm

using mirror formula:

1/u+1/v=1/f

1/u-3/u=1/60

u=-120cm

Explanation:

Answer 2

Answer:

Explanation:

Given:

u=-60cm

m=1/2

m=-v/u

1/2=-v/-60

-v=-30cm

v=30cm

f=?

by mirror formula:

-1/60+1/30=1/f

on solving:

f=60cm

m=1/3

1/3=-v/u

v=(1/3)u

f=60cm

using mirror formula:

1/u+1/v=1/f

1/u-3/u=1/60

u=-120cm