JEE PHYSICS MCQ: RAY OPTICS

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Assertion: A concave mirror and convex lens both have the same focal length in air. When they are submerged in water, they will have same focal length.

Reason: The refractive index of water is smaller than the refractive index of air.

View answer and explanation

Correct option: D

If the assertion and reason both are false.

Option D (If the assertion and reason both are false) is correct because the focal length of a mirror doesn't change in water, but the focal length of a lens does change, and the refractive index of water is greater than air.

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