Question

A concave mirror of focal lenght 8 cm produces a real image which is four times the size of the object. how far is the object from the mirror?

Answer 1

Answer:

The object will be 10cm far from the mirror.

Explanation:

GIVEN

Focal Length= f = 8cm

Nature of Image= Real Image

Magnification of Image= M = 4

REQUIRED

Object Distance= p = ?

SOLUTION

By LINEAR MAGNIFICATION:

M= q/p

4=q/p

q=4p

By THIN LENS FORMULA:

1/f= 1/p + 1/q

1/8= 1/p + 1/4p

1/8= 4+1/4p

1/8=5/4p

4p= 8×5

4p= 40

p=40/4

p=10cm

Answer 2

Answer:10 cm

Explanation: