Question

find the power of convex lens which forms a real and inverted image of magnification of an object placed at a distance of 20 cm from optic centre​

Answer 1

Answer:

10D

Explanation:

Since 1/v-1/u=1/f

u=-20cm and v=20cm

Therfore, 1/20-(-1/20)=1/f

2/20=1/f

f=10

since power=100/f(cm)

p=100/10=10d

Answer 2

Answer:

Explanation:

1/v-1/u=1/f

u=-20cm and v=20cm

Therfore, 1/20-(-1/20)=1/f

2/20=1/f

f=10

since power=100/f(cm)

p=100/10=10d

So the ans is 10 diopter/D