Two opposite and equal charges $4 \times 10^{-8}$ coulomb w…

Physics Electrostatics Potential & Capacitance Electric Force Single Correct MCQ

Published on: September 12, 2026

Two opposite and equal charges $4 \times 10^{-8}$ coulomb when placed $2 \times 10^{-2} \, cm$ away, form a dipole. If this dipole is placed in an external electric field $4 \times 10^{8} \text{ newton/ coulomb}$ , the value of maximum torque and the work done in rotating it through $180^{\circ}$ will be

$64 \times 10^{-4} \ \mathrm{Nm}$ and $64 \times 10^{-4} \, \mathrm{J}$

$32 \times 10^{-4}$ Nm and $32 \times 10^{-4} J$

$64 \times 10^{-4} \ \mathrm{Nm}$ and $32 \times 10^{-4} J$

$32 \times 10^{-4} \ \mathrm{Nm}$ and $64 \times 10^{-4} \, J$

Text Solution

Verified by Experts

The correct answer is:

Dipole moment p = 4 × × 10 –8 × × 2 × × 10 –4 = 8 × × 10 –12 m

Maximum torque = pE = 8 × × 10 –12 × × 4 × × 10 8

= 32 × × 10 –4 Nm

Work done in rotating through 180 o = 2pE

= 2 × × 32 × × 10 –4 = 64 × × 10 –4 J

Previous Question Next Question

Prepare Smarter with CGP Edu

Get practice questions, solutions, and test series in one place.

Write a Review

Share your experience with this question and solution.

Commentary

Send your comment, doubt, correction, or feedback to admin.

Student Reviews

What students say about this solution

No reviews yet. Be the first to write a review.

Share this question

Text Solution

Prepare Smarter with CGP Edu

Write a Review

Commentary

Student Reviews

Similar Questions