Question

An object is paced at a distance of 20 cm from a concave mirror the image is double the size of the object and is inverted fi d the focal length of the mirror and position
Where image forms

Answer 1

Answer:

Explanation:

(a) Given for the real image

Magnification, m=-3

Object distance, u=-20cm

Magnification, m=-v/u

-3=- v/(-20)

v=-60 cm

Thus the image is located at a distance of 60cm in front of the mirror.

Now using the mirror formula,

1/v +1/u=1/f

1/(-60) + 1/(-20)=1/f

f=-15 cm

(b) For virtual image

m= 3 and f= -15 cm

m=h2 /h1=- v/u=3

v=-3u

Using mirror formula,

1/(-3u) +1/u=1/-15

u=-10 cm

so object should be placed 10 cm from the concave mirror