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Physics · Gravitation

JEE Main 2025 — 4 April, Morning Shift — Question 58

Given below are two statements: one is labelled as Assertion A\mathbf{A} and the other is labelled as Reason R\mathbf{R}

Assertion A : The kinetic energy needed to project a body of mass mm from earth surface to infinity is 12mgR\frac{1}{2} m g R, where RR is the radius of earth.

Reason R: The maximum potential energy of a body is zero when it is projected to infinity from earth surface.

In the light of the above statements, choose the correct answer from the options given below.

  1. Option A:

    A\mathbf{A} is true but R\mathbf{R} is false

  2. Option B:

    A\mathbf{A} is false but R\mathbf{R} is true

    Correct
  3. Option C:

    Both A\mathbf{A} and R\mathbf{R} are true but R\mathbf{R} is NOT the correct explanation of A\mathbf{A}

  4. Option D:

    Both A\mathbf{A} and R\mathbf{R} are true but R\mathbf{R} is the correct explanation of A\mathbf{A}

Answer: B

Step-by-step solution

12mv2−GMmR=0\frac{1}{2} m v^{2}-\frac{G M m}{R}=0

KE=GMR2⋅mR\mathrm{KE}=\frac{\mathrm{GM}}{R^{2}} \cdot m R

=mgR=m g R

A is false

PE at infinity is zero

R\mathbf{R} is true.

Answer key and solution verified before publishing.

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Exam
JEE Main 2025
Paper
4 April, Morning Shift
Subject
Physics
Chapter
Gravitation
Topic
Motion of Satellites and Escape Speed
Given below are two statements: one is labelled as Assertion A and… | JEE Main 2025 PYQ with Solution · DhiX AI