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Question 31472
JEE Physics · Hard

Electrostatics: Potential Energy MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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Potential EnergyHardQuestion 31472

Question

Two protons (charge e, mass m) are released from rest at separation r₀. Speed of each when separation doubles:
  1. A
    √(ke²/(mr₀))
  2. B
    √(ke²/(2mr₀))
    Correct
  3. C
    √(2ke²/(mr₀))
  4. D
    √(ke²/(4mr₀))

Correct answer

√(ke²/(2mr₀))

Explanation

Energy conservation: ke²/r₀ = ke²/(2r₀) + 2×½mv². ke²/(2r₀) = mv². v = √(ke²/(2mr₀)).

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