JEE Main 2025 — Magnetic Properties of Matter Question with Solution
JEE Main 2025 (28 Jan Shift 2)
Question
A bar magnet has total length units and the field point is at a distance units from the centre of the magnet. If the relative uncertainty of length measurement is , then uncertainty of the magnetic field at point P is :
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Show full solutionCorrect option: A
Correct answer
A
Step-by-step explanation
Magnetic field at , where is the pole strength $\begin{aligned} \Rightarrow\left(\frac{\Delta B}{B} \times 100\right) & =\left(\frac{\Delta l}{l}\right) \times 100+3\left|\frac{\Delta r}{r}\right| \times 100 \\ & =1 \%+3 \%=4 \% \end{aligned}$
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This is a previous-year question from JEE Main 2025, covering the Magnetic Properties of Matter chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.