Question

Reciprocal of focal length in metres is known as the
A) focus
C) four point
B) power
D)radius
curvature​

Answer 1

Answer:

The answe is option B) Power.

Explanation:

• The distance between the centre of the curvature of the lens and it's focal point is known as focal length.
• The distance between the centre of the curvature of the lens and it's focal point is known as focal length.The focus is the point where any ray coming from infinity meet after getting reflected or refracted.
• The distance between the centre of the curvature of the lens and it's focal point is known as focal length.The focus is the point where any ray coming from infinity meet after getting reflected or refracted.The power of a lens is defined as the reciprocal of its focal length.

That is P = 1/ƒ where ,

P stands for power of the lens and ƒ stands for the focal length.

Similarly by rearranging a little bit we can also see that focal length is the reciprocal of power that is ƒ = 1/P.

So the correct answer is option B)Power.

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