Question

an object has image thrice of its original size when kept at 8cm and 16 cm from a convex lens.focal length of the lens​

Answer 1

Answer:

Explanation:

=> An object has image thrice of its original size when kept at 8cm and 16 cm from a convex lens.

m = ± 3

=> now, by using m = f /  f + u formula, we can calculate the focal length.

For virtual image:

3 = f /l f - 8 ... (1)

For real image:

-3 = f / f - 16 ...(2)

From  eq (i) and (ii), we get

f = 12 cm

Thus, focal length of the lens is 12 cm which comes between 8 cm and 16 cm.

Answer 2

Answer:

see the answer image thank you