Question

An object Kept ala distance of 20cm
infront of a concave mirror the focal length,
of a mirror is zoom
what is magnification​

Answer 1

Correct Question !!

An object Kept at distance of 20cm

infront of a concave mirror the focal length,

of a mirror is 30cm .what is magnification

Given:-

• Object distance,u = -20cm

• Focal length,f = -30cm

To Find:-

• Magnification,m

Solution:-

Firstly we calculate the position of image.

By using mirror formula

• 1/v + 1/u = 1/f

Substitute the value we get

→ 1/v = 1/f -1/u

→ 1/v = -1/30 +1/20

→ 1/v = -2+3/60

→ 1/v = 1/60

→ v = 60 cm

Now, calculating the magnification

• magnification ,m = -v/u

Substitute the value we get

→ m = -60/-20

→ m = 60/20

→ m = 3cm

Therefore, the magnification of the mirror is 3cm.