Question

Define power of a lens and write its SI unit.

Answer 1

If focal length of a lens is 1 metre its power is 1 D

SI unit -Dioptre is its SI unit denoted by D

Answer 2

✨✔️✔ ️HERE IS YOUR ANSWER...

✔ ️The power of lens is defined as the reciprocal of its focal length.

✔️ It is represented by the letter “P”.

✔ ️$p = \frac{1}{f}$

✔️ The SI unit of power of lens is “dioptre”.
• It is denoted by the letter “D”.
• 1 D is the power of a lens whose focal length is 1m.

✔️ Power of a convex lens is positive.

✔️ Power of a concave lens is negative.

✨✔️✔️ HOPE IT HELPS YOU....
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