Question

an object is placed 20 cm from a convex lens of focal length 10 cm . the image must be​

Answer 1

Answer:

Hi hope it helps

Explanation:

u=-20cm

f=+10cm

v=??

1/f=1/v-1/u

1/10=1/v+1/20

1/v=1/10-1/20

1/v=1/20

v=+20cm

Now,

m=v/u

m=20/-20

m=-1

So image is real,inverted and is of same size.

Answer 2

Answer:

CONVEX LENS

f = 10 cm

u = - 20 cm

It means the object is placed at 2f1

So the image will bd formed on 2f2

Hence, v = 20 cm

image formed will be real and inverted also size of image will be equal to the size of object.

(You will get the same conclusions on solving it numerically as solved in the above user's answer)

so,

IMAGE MUST BE AT 20 CM FROM THE LENS, SAME SIZE TO THE OBJECT ALSO REAL AND INVERTED.