Question

Find the size,nature and position of the image formed when an object of 1cm height is placed at a distance of 15cm from a concave mirror of focal length 1 cm.

Answer 1

QUESTION -

Find the size,nature and position of the image formed when an object of 1cm height is placed at a distance of 15cm from a concave mirror of focal length 1 cm.

ANSWER -

Concave mirror:

u = -15 cm, f = -1 cm, v =?

Mirror formula : 1/u + 1/v = 1/f

1/-15 +1/v = 1/-1

1/v = -1 +1/15 = - 14/15

v = - 14/15 cm

Magnification, m = -v/u = -(-14/15)/-15 = - 14/225

Now, h2/h1 = m

h2 = h1×m = 1 ×-2 = -2 cm

Answer 2

Answer:

Correct Question:-

Find the size,nature and position of the image formed when an object of 1cm height is placed at a distance of 15cm from a concave mirror of focal length 10 cm.

Answer:-

This here

f = -10 cm

u = -15cm

h(height of object) = 1cm

we have to find

size , nature , position of image formed .

Thus using mirror equation :-

1/f = 1/u+1/v

=>1/v = 1/f-1/u

=> 1/v = -1/10+1/15

=> 1/v = -1/30

=> v = -30 { thus image will be formed beyond center

Now magnification

m = -(v/u) = h'/h

m = -(-30/-15)

=> m = -2

HENCE the image formed will be real and inverted and magnified.

Now m = h'/h

2 = h'/1

=> h' = 2cm

hence the size of the image will be doubled