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    Question

    If a near-sighted person cannot see objects clearly

    beyond 1.2 meters, what should be the focal length of the concave lens required for correction?
    A 1.5 m Correct Answer Incorrect Answer
    B 1.2 m Correct Answer Incorrect Answer
    C 2.2 m Correct Answer Incorrect Answer
    D 2.5 m Correct Answer Incorrect Answer

    Solution

    Sol. For a person with myopia (near-sightedness), the focal length of the concave lens should equal the farthest distance at which the person can see clearly. Here, the required focal length is 1.2 meters. Information Booster:

    • Myopia is corrected using a concave lens.
    • It occurs due to an elongated eyeball or a steep cornea.
    • Concave lenses help focus light farther away.
    • Commonly develops during childhood.
    • Proper eyeglasses or contact lenses help correct the vision.
    ---:
    • 1.5 m: Suitable for moderate myopia.
    • 2.2 m: Can apply to hyperopia cases.
    2.5 m: Used in severe vision defects.

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