JEE Main 2019PhysicsOscillationsHardMCQ

JEE Main 2019 — Oscillations Question with Solution

JEE Main 2019 (09 Apr Shift 1)

Question

A simple pendulum oscillating in air has period T . The bob of the pendulum is completely immersed in a non-viscous liquid. The density of the liquid is 116th of the material of the bob. If the bob is inside liquid all the time, its period of oscillation in this liquid is:

Choose an option

Show full solutionCorrect option: C
Correct answer
C4T115

Step-by-step explanation

Let the density of bob is σ & density of liquid is  σ16 .
Now, Net downward force on bob = Weight - Buoyancy
=σVg-σ16Vg =1516σVg
Net effective gravitational acceleration = 1516σVgσV= 1516g
Time period T=2πlgeff=2πl1516g=2π1615lg=1615∙2πlg=415T
=4T115

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About this question

This is a previous-year question from JEE Main 2019, 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.