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Question 20216
JEE Physics · Hard

Magnetism: Cyclotron — Proton vs Deuteron MCQ

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Cyclotron — Proton vs DeuteronHardQuestion 20216

Question

A proton and deuteron enter a cyclotron with the same kinetic energy. The ratio of their radii (r_p/r_d) in the same field B is:
  1. A
    1/2
  2. B
    1/√2
    Correct
  3. C
    √2
  4. D
    2

Correct answer

1/√2

Explanation

r = mv/qB = √(2mKE)/(qB). r ∝ √m/q. For same KE and same q: r_p/r_d = √(m_p/m_d) = √(1/2) = 1/√2.

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