Easy MCQ +4 / -1 PYQ · JEE Mains 2025

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

Assertion A : Work done in moving a test charge between two points inside a uniformly charged spherical shell is zero, no matter which path is chosen.

Reason R : Electrostatic potential inside a uniformly charged spherical shell is constant and is same as that on the surface of the shell.

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

  1. A <p>A is true but R is false</p>
  2. B <p>Both A and R are true and R is the correct explanation of A</p> Correct answer
  3. C <p>Both A and R are true but R is NOT the correct explanation of A</p>
  4. D <p>A is false but R is true</p>

Solution

<p>$\textbf{Assertion A:}$ </p> <p><p>For a uniformly charged spherical shell, Gauss's law tells us that the electric field inside the shell is zero. </p></p> <p><p>Since the electric field $\vec{E}$ is zero everywhere inside, the potential $V$ must be constant. </p></p> <p><p>Work done in moving a charge from one point to another in an electric field is given by the difference in potential energy, which is $q(V_B - V_A)$. </p></p> <p><p>If the potential difference $V_B - V_A$ is zero (because the potential is constant), then the work done is zero, regardless of the path taken. </p></p> <p><p>Therefore, Assertion A is true.</p></p> <p>$\textbf{Reason R:}$ </p> <p><p>It states that the electrostatic potential inside a uniformly charged spherical shell is constant and equal to that on its surface. </p></p> <p><p>This is correct because the electric field inside is zero, ensuring that the potential remains uniform inside. </p></p> <p><p>Thus, Reason R is also true.</p></p> <p>$\textbf{Relationship between A and R:}$ </p> <p><p>The work done on a test charge moving inside the shell being zero is a direct consequence of the fact that the potential is constant inside. </p></p> <p><p>Hence, Reason R correctly explains why the work done (Assertion A) is zero.</p></p> <p>Given this analysis, the correct answer is:</p> <p>Option B </p> <p>"Both A and R are true and R is the correct explanation of A."</p>

About this question

Subject: Physics · Chapter: Electrostatics · Topic: Coulomb's Law

This question is part of PrepWiser's free JEE Main question bank. 132 more solved questions on Electrostatics are available — start with the harder ones if your accuracy is >70%.

Drill 25 more like these. Every day. Free.

PrepWiser turns these solved questions into a daily practice loop. Chapter-wise drills, full mocks, AI doubt chat. No auto-renew.

Start free →