Power of Lens nbsp-i- What will be the focal length of a lens having power 2-5 m-1- nbsp-Is the lens converging or diverging- nbsp-40 cm converging- nbsp-ii- Calculate the power of a convex lens having focal length nbsp-20 cm nbsp- nbsp-

Dear Student, since the power is +ve the lens would be convex that is converging nbsp; f=1/2.5m=100/2.5 cm =40 cm . regards ...

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Standard X

Physics

Myopia

Power of Lens...

Question

Power of Lens
(i) What will be the focal length of a lens having power 2.5 m^-1? Is the lens converging or diverging?
[40 cm converging]

(ii) Calculate the power of a convex lens having focal length 20 cm

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Solution

Dear Student,

since the power is +ve the lens would be convex that is converging
f=1/2.5m=100/2.5 cm =40 cm .

regards

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Similar questions

(a) What do you understand by the power of a lens? Name one factor on which the power of a lens depends.

(b) What is the unit of power of a lens? Define the unit of power of a lens.

(c) A combination of lenses for a camera contains two converging lenses of focal lengths 20 cm and 40 cm and a diverging lens of focal length 50 cm. Find the power and focal length of the combination.

Q. A lens of power

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Q. A convex lens of focal length

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A person has near point of his vision shifted to 50 cm. What lens must be used to see an object placed at 25 cm from the eye? What is the power of the lens?

Q. Solve the following examples.
i. Doctor has prescribed a lens having power +1.5 D. What will be the focal length of the lens? What is the type of the lens and what must be the defect of vision?
ii. 5 cm high object is placed at a distance of 25 cm from a converging lens of focal length of 10 cm. Determine the position, size and type of the image.
iii. Three lenses having power 2, 2.5 and 1.7 D are kept touching in a row. What is the total power of the lens combination?
iv. An object kept 60 cm from a lens gives a virtual image 20 cm in front of the lens. What is the focal length of the lens? Is it a converging lens or diverging lens?

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Power of Lens (i) What will be the focal length of a lens having power 2.5 m-1? Is the lens converging or diverging? [40 cm converging] (ii) Calculate the power of a convex lens having focal length 20 cm

Dear Student, since the power is +ve the lens would be convex that is converging f=1/2.5m=100/2.5 cm =40 cm . regards

Power of Lens
(i) What will be the focal length of a lens having power 2.5 m^-1? Is the lens converging or diverging?
[40 cm converging]

(ii) Calculate the power of a convex lens having focal length 20 cm

Dear Student,

since the power is +ve the lens would be convex that is converging
f=1/2.5m=100/2.5 cm =40 cm .

regards