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Friday, 9 October

NEET UG 2021 · Physics · Question 18

NEET 2021 Physics, question 18

Question 18 of the NEET 2021 paper (code O1) is a Physics question from Moving Charges and Magnetism. Its idea, Force on Charge Moving Parallel to Wire, was asked only this once in NEET 2017–2026. The NTA final answer key gives option 2.

Updated 2026-10-08

Q18 · Physics

An infinitely long straight conductor carries a current of 5 A as shown. An electron is moving with a speed of 10510^{5} m/s parallel to the conductor. The perpendicular distance between the electron and the conductor is 20 cm at an instant. Calculate the magnitude of the force experienced by the electron at that instant.

The figure, described in words

Stem: figure of long straight conductor PQ carrying 5 A with an electron of speed 10^5 m/s moving parallel, perpendicular distance 20 cm marked.

  1. 14π×10−204\pi\times10^{-20} N
  2. 28×10−208\times10^{-20} NOfficial answer
  3. 34×10−204\times10^{-20} N
  4. 48π×10−208\pi\times10^{-20} N

Official answer: option 2 · NTA final answer key

Same idea

The only question on Force on Charge Moving Parallel to Wire

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

Force on Charge Moving Parallel to Wire: 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. Ampere's Circuital Law alone had 8.

Chapter analysisStudy this chapterPractise this chapter

Moving Charges and Magnetism: questions per paper

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