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.

Magnetic Effects & Magnetism

JEE Main level, single correct, medium

119 of 276

Question 119 of 276

A proton and a deutron ( $q=+\mathrm{e}, m=2.0 \mathrm{u})$ having same kinetic energies enter a region of uniform magnetic field $\vec{B}$ , moving perpendicular to $\vec{B}$ . The ratio of the radius $r_d$ of deutron path to the radius $r_p$ of the proton path is:

Show answer and solution

Answer: (A) $\sqrt{2}: 1$

In uniform magnetic field,

\mathrm{R}=\frac{\mathrm{m} \nu}{\mathrm{qB}}=\frac{\sqrt{2 \mathrm{~m}(\mathrm{~K} . \mathrm{E})}}{\mathrm{qB}}

Since same K.E

\begin{aligned}& \mathrm{R} \propto \frac{\sqrt{\mathrm{m}}}{\mathrm{q}} \\& \therefore \frac{\mathrm{R}_{\text {deutron }}}{\mathrm{R}_{\text {proton }}}=\sqrt{\frac{\mathrm{m}_{\mathrm{d}}}{\mathrm{m}_{\mathrm{p}}}} \times \frac{\mathrm{q}_{\mathrm{p}}}{\mathrm{q}_{\mathrm{d}}} \\& =\sqrt{2} \times 1 \\& \therefore \gamma_{\mathrm{d}}: \gamma_{\mathrm{p}}=\sqrt{2}: 1\end{aligned}

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 Magnetic Effects & Magnetism (Motion of Charged Particle in Magnetic Field), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.