Question

An object of 4 cm height is placed at 6 cm in front of a concave mirror of radius of curvature 24 cm. Find the position, height, magnification and nature of the image.

Answer 1

h = 4 cm

u = - 6 cm

R = - 24 cm

f = `"R"/2 = (- 24)/2` = - 12 cm

Find out: v = ?, I = ?, m = ?

Mirror formula,

1) `1/"f" = 1/"v" + 1/"u"`

`(-1)/12 = 1/"v" - 1/6`

`1/"v" = - 1/12 + 1/6`

`1/"v" = (- 1 + 2)/12 = 1/12`

v = 12 cm

2) `("I" ("h'"))/"h" = (- "v")/"u"`

I(h') = (- "v")/"u" (h)

`= (- 12)/(- 6)`

h' = 8 cm

3) m = `"I"/"O" = ("h"')/"h" = 8/4 = 2` 

m = 2