JEE PHYSICS MCQ: RAY OPTICS

1 Medium

1 of 1

Analyzing +4 | -1

Assertion: A double convex lens

(\mu=1.5)

has focal length

10 \mathrm{~cm}

. When the lens is immersed in water

(\mu=4 / 3)

its focal length becomes

40 \mathrm{~cm}

.
Reason:

\frac{1}{f}=\frac{\mu_1-\mu_m}{\mu_m}\left(\frac{1}{R_1}-\frac{1}{R_2}\right)

View answer and explanation

Correct option: A

If both assertion and reason are true and the reason is the correct explanation of the assertion

Option A (If both assertion and reason are true and the reason is the correct explanation of the assertion) is correct because the focal length changes as described, and the lensmaker's formula explains this change.

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