Question

an object is placed on yhe principal axis of a concave mirror of focal length 24cm.if the image distance is 20cm more than the object distance find the magnification.​

Answer 1

Answer:

Given that,

f = -24 cm (it is negative for concave mirror)

Let u is the object distance and v is the image distance. According to given condition, the image distance is 20 m more than the object distance,

v = 20 + u

We can find the object distance from the mirror using mirror's formula.

u = -8 cm

Image distance becomes,

v = 20 + (-8)

v = 12 cm

The magnification of the mirror is given by :

m = -v/u

m= -12/-8

m = 1.5

I hope this is helpful...

Answer 2

Magnification = 1.5

Explanation:

Given concave mirror of focal length f = -24 cm. f is negative for concave mirrors.

Image distance = v = u + 20 cm

Object distance = u

1/f = 1/v - 1/u

Solving, we get u = -8 cm (object distance)

So, image distance = u + 20 = -8 + 20 = 12 cm

Magnification of the concave mirror, m = -v/u

m = -12/-8

m = 1.5