Question

When a pin of height 2cms is fixed at 10cms from a convex lens, the height of virtual image formed is 12cms .Find the focal length of the lens.​

Answer 1

Answer:

SORRY I DID NOT KNOW BIT STILL I WILL TRY.

Explanation:

h2h1=vu

∴12cm3cm=v−10cm ∴v=−40cm

Now 1f=1v−1u

∴1f=1−40cm=1−10cm=110cm−140cm

= 4−140cm=340cm

f=403cm=13.33 cm ( approximately) '

The focal length of the lens = 13.33 cm [ approximately].