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Question 20174
JEE Physics · Medium

Magnetism: Velocity Selector MCQ

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Velocity SelectorMediumQuestion 20174

Question

In a velocity selector, a charged particle passes undeflected when:
  1. A
    qE = qvB
    Correct
  2. B
    qE = mv²/r
  3. C
    qvB = mv²/r
  4. D
    E = B²

Correct answer

qE = qvB

Explanation

The particle is undeflected when electric force equals magnetic force: qE = qvB → v = E/B. The selector is speed-selective.

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