Doctor has prescribed a lens having power $+ 1.5 D$ . What would be the focal length of the lens? What is the type of lens and what must be the defeat of vision?

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Solution

A lens having a power +1.5 D will have a focal length of
P =1/f
+1.5 D = 1/f
f = 1/1.5 = 2/3 = + 0.67 m.
The focal length is + 0.67m.
The nature of lens is converging type or convex lens.
The defect of the eye is Hyperopia or far-sightedness.

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Similar questions

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?

Q. A doctor has prescribed a corrective lens of power

+ 1.5 D

. Find the focal length of the lens. Is the prescribed lens diverging or converging?

Question 17
A doctor has prescribed a corrective lens of power +1.5 D. Find the focal length of the lens. Is the prescribed lens diverging or converging?

A doctor has prescribed a corrective lens of power+1.5 doctor. Find the focal length

(a) is the prescribed lens diverging or converging

Q. A person needs a lens of power, −5.5 D for correcting his distant vision. For correcting his near vision, he needs a lens of power, + 1.5 D. What is the focal length of the lens required for correcting:
(a) distant vision?
(b) near vision?
What type of lens is being used for correcting (i) distant vision, and (ii) near vision?

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Doctor has prescribed a lens having power +1.5D. What would be the focal length of the lens? What is the type of lens and what must be the defeat of vision?

A lens having a power +1.5 D will have a focal length ofP =1/f+1.5 D = 1/ff = 1/1.5 = 2/3 = + 0.67 m.The focal length is + 0.67m.The nature of lens is converging type or convex lens.The defect of the eye is Hyperopia or far-sightedness.

Doctor has prescribed a lens having power $+ 1.5 D$ . What would be the focal length of the lens? What is the type of lens and what must be the defeat of vision?

A lens having a power +1.5 D will have a focal length of
P =1/f
+1.5 D = 1/f
f = 1/1.5 = 2/3 = + 0.67 m.
The focal length is + 0.67m.
The nature of lens is converging type or convex lens.
The defect of the eye is Hyperopia or far-sightedness.