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Friday, 9 October

NEET UG 2025 · Physics · Question 3

NEET 2025 Physics, question 3

Question 3 of the NEET 2025 paper (code 45) is a Physics question from Moving Charges and Magnetism. Its idea, Crossed E and B Fields, was asked only this once in NEET 2017–2026. The NTA final answer key gives option 2.

Updated 2026-10-08

Q3 · Physics

An electron (mass 9×10−319\times10^{-31} kg and charge 1.6×10−191.6\times10^{-19}C) moving with speed c/100 (c = speed of light) is injected into a magnetic field B⃗\vec{B} of magnitude 9×10−49\times10^{-4} T perpendicular to its direction of motion. We wish to apply an uniform electric field E⃗\vec{E} together with the magnetic field so that the electron does not deflect from its path. Then (speed of light c = 3×1083\times10^8 ms−1^{-1})

  1. 1E⃗\vec{E} is perpendicular to B⃗\vec{B} and its magnitude is 27×10427\times10^4 V m−1^{-1}
  2. 2E⃗\vec{E} is perpendicular to B⃗\vec{B} and its magnitude is 27×10227\times10^2 V m−1^{-1}Official answer
  3. 3E⃗\vec{E} is parallel to B⃗\vec{B} and its magnitude is 27×10227\times10^2 V m−1^{-1}
  4. 4E⃗\vec{E} is parallel to B⃗\vec{B} and its magnitude is 27×10427\times10^4 V m−1^{-1}

Official answer: option 2 · NTA final answer key

Same idea

The only question on Crossed E and B Fields

No other NEET paper from 2017–2026 tested this exact idea.

Crossed E and B Fields: every question and how it was framed

The chapter

Moving Charges and Magnetism in ten years of NEET

22 questions from 2017–2026, asked in 10 of 10 papers, about 2.1 a paper. Magnetic Force on Charges and Currents alone had 10.

Chapter analysisStudy this chapterPractise this chapter

Moving Charges and Magnetism: questions per paper

0242’172’182’191’204’213’222’231’243’252’26