Question

An object of height 10 cm is placed at a distance of 20 cm in front of a mirror. Its image is found at the same distance when it is placed. A. What is the type of the mirror? B. Is the image real or virtual? C. What is the height of the image?

Answer 1

Answer:

ANSWER

Given that,

Focal length f=

2

R

Radius of curvature R=30

Object distance u=10cm

Height of object h

o

=2cm

From the mirror formula,

f

1

=

v

1

+

u

1

−

v

1

=

u

1

−

f

1

−

v

1

=

10

1

−

30

2

−

v

1

=

30

3−2

v=−30cm

Now, the magnification is

m=

u

−v

m=

10

30

m=3

Now, the height of image

m=

h

o

h

i

3=

2

h

i

h

i

=6cm

Hence, the image distance is −30 cm, height of image is 6 cm and magnification is 3