Physics, asked by meenuzzzz, 1 year ago

what is power of lens? define in 30 words.

Answers

Answered by kvnmurty
4
The correct definition of the power of a lens is as follows:

The power P of a lens is defined as the tangent of the angle δ by which it converges or diverges a beam of light falling at unit distance (1 m) from the optical centre (pole).
 
    tan δ = h / f    and     if  h = 1 meter,    tan δ = 1/f    or,   δ =  1 / f
  
     thus   P = 1 / f 

Thus the angle at which, a ray parallel to principal axis and 1 meter distance from it, is converged or diverged is the power of lens.

       P = 1 / f   is the way we calculate the power.  It is not the definition.

The focal length is in meters.  Unit of Power of lens is called Doptres. It is positive for the convex lens and negative for the concave lens.


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kvnmurty: click on thank you link
kaushikravikant: hello, he was telling about power
kaushikravikant: Donot show your extra knowledge
kvnmurty: the correct definition is what i mentioned... thanks for your advice.
kvnmurty: read your book please.
kaushikravikant: Oh. I have written wrong
kvnmurty: thanx meenu.
kaushikravikant: he ask your answer in 3o word, there is word limit of this answer
Answered by Ajeesha15
3
✨✔️✔ ️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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