A planet ( P 1 ) is moving around the star of mass 2M in the orbit of radius R. Another planet ( P 2 ) is moving around another star of mass 4M in a orbit of radius 2R. Ratio of time periods of revolution of P 2 and P 1 is

Physics · Gravitation

JEE Main 2026 — 2 April, Morning Shift — Question 4

A planet $(\mathrm{P}_{1})$ is moving around the star of mass 2M in the orbit of radius R. Another planet $(\mathrm{P}_{2})$ is moving around another star of mass 4M in a orbit of radius 2R. Ratio of time periods of revolution of $\mathrm{P}_{2}$ and $\mathrm{P}_{1}$ is

Option A:
$\frac{1}{2}$
Option B:
2
Correct
Option C:
4
Option D:
$\frac{1}{4}$

Answer: B

Step-by-step solution

From Kepler's law, $\mathrm{T}^{2} = \frac{4\pi^{2}}{\mathrm{GM}_{\mathrm{S}}}\mathrm{r}^{3}$ ... $\frac{\mathrm{T}_{\mathrm{P}_{2}}}{\mathrm{T}_{\mathrm{P}_{1}}} = 2$ .

Answer key and solution verified before publishing.

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Exam: JEE Main 2026
Paper: 2 April, Morning Shift
Subject: Physics
Chapter: Gravitation
Topic: Motion of Satellites and Escape Speed