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JEE Main 202522 JanuaryEvening Shift
Exam
JEE Main
Year
2025
Date
22 January
Shift
Evening Shift
Subject
Physics
Chapter
Oscillations

JEE Main 2025 · 22 January · Evening Shift · Physics · Oscillations

Given below are two statements. One is labelled as Assertion (A)...

Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : A simple pendulum is taken to a planet of mass and radius, 4 times and 2 times, respectively, than the Earth. The time period of the pendulum remains same on earth and the planet. Reason (R): The mass of the pendulum remains unchanged at Earth and the other planet. In the light of the above statements, choose the correct answer from the options given below :

Options

  1. A(A)(\mathbf{A}) is false but (R) is true
  2. B(A) is true but (R) is false
  3. CBoth (A)(\mathbf{A}) and (R)(\mathbf{R}) are true and (R)(\mathbf{R}) is the correct explanation of (A)(\mathbf{A})
  4. DBoth (A) and (R) are true but (R) is NOT the correct explanation of (A)

Correct answer

D. Both (A) and (R) are true but (R) is NOT the correct explanation of (A)

Step-by-step solution

g=GMR2g′=G(4M)(2R)2=g\begin{aligned} & g=\frac{G M}{R^2} \\ & g^{\prime}=\frac{G(4 M)}{(2 R)^2}=g \end{aligned} A is correct, RR is correct ; but since T=2πℓgT=2 \pi \sqrt{\frac{\ell}{g}} doesn't depend on mass ; R doesn't explain A .
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