Doubtclip is an AI tutor that turns any homework or exam doubt into a step-by-step whiteboard video lesson with diagrams, formulas, and voice explanation.

Which subjects and exams does it support?

It supports Physics, Chemistry, Mathematics/Calculus and related STEM doubts for school boards, JEE, NEET, and global high-school / undergrad practice.

How do I get a video solution?

Upload a photo of the question or paste the text, sign in, and Doubtclip generates a whiteboard-style explanation video you can watch and share.

Is Doubtclip available worldwide?

Yes. Doubtclip is a web app for students globally. Lessons are available in English and Hinglish.

Electromagnetic Waves

JEE Main level, single correct, medium

76 of 165

Question 76 of 165

A light beam is described by $E=800\sin \omega \left(t-\dfrac{x}{c}\right).$ An electron is allowed to move normal to the propagation of light beam with a speed of $3\times {10}^{7}{ms}^{-1}$ . What is the maximum magnetic force exerted on the electron?

Show answer and solution

Answer: (B) $12.8\times {10}^{-18}N$

{E}_{0}=800V

{B}_{0}=\dfrac{{E}_{0}}{c}=\dfrac{800}{3\times {10}^{8}}

{F}_{m}=qv{B}_{0}=\dfrac{1.6\times {10}^{-19}\times 3\times {10}^{7}\times 800}{3\times {10}^{8}}

=12.8\times {10}^{-18}N

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Electromagnetic Waves (Electromagnetic Waves and Maxwell's equations), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.