JEE Main 2022PhysicsOscillationsMediumNumerical

JEE Main 2022 — Oscillations Question with Solution

JEE Main 2022 (29 Jul Shift 2)

Question

The metallic bob of simple pendulum has the relative density 5. The time period of this pendulum is 10 s. If the metallic bob is immersed in water, then the new time period becomes 5x s. The value of x will be _____ .

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Show full solutionCorrect answer: 5
Correct answer
5

Step-by-step explanation

When the bob is immersed in water its effective weight is mg'=mg-FB, where, FB is buoyant force.

Then, g'=mg-FBm =ρBVg-ρWVgρBV

=ρB-ρwρBg =5-15×g=45g

Now, time period of simple pendulum is given by T=2πlg

Thus, the ratio T'T=gg'=g45g=54

⇒T'=T54=1025

Thus, the new time period is T'=55 s. 

Hence, value of x=5.

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About this question

This is a previous-year question from JEE Main 2022, covering the Oscillations chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.