Question

a concave mirror of focal length 10 cm is kept in front of an object at a distance of 50 cm front it if the object is 1 am high what will be the size of the image

Answer 1

Answer:

An object is placed 30 cm in front of a concave mirror of focal length 20 cm. What is the distance between the object and the image?

Given,

u=30 cm

f=20 cm

v=?

Here,

1/u + 1/v = 1/f

1/30 + 1/v = 1/20

1/v = 1/20 - 1/30

1/v = 1/60 (use calculator )

v= 60 cm

( u, v, f are always in ‘+’ in concave.

But ‘-’ in convex)

Now,

(Since image is formed on the same side of the object , the image is real)

v-u = 60 - 30 = 30 cm

So the distance between object and image is 30 cm.