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Question 30671
JEE Physics · Hard

Circular Motion: Advanced — Charged Particle in B Field MCQ

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Advanced — Charged Particle in B FieldHardQuestion 30671

Question

A proton (mass m, charge q) moves in a circle of radius r in a magnetic field B. Its speed is:
  1. A
    qBr/m
    Correct
  2. B
    mBr/q
  3. C
    qB/mr
  4. D
    qmB/r

Correct answer

qBr/m

Explanation

Magnetic force = centripetal force: qvB = mv²/r → v = qBr/m.

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