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MHT CET202620 April 2026Morning ShiftPhysicsElectrostaticsActual

Two point charges q₁ and q₂ are ' l ' distance apart. If one of the charges is doubled and the distance between them is halved. The magnitude of the force becomes 'n' times, where 'n' is

Options

  1. A2
  2. B4
  3. C8
  4. D16

Correct answer

C. 8

Step-by-step solution

Initial force between the charges is given by Coulomb's law: F = 1 4 ₀ q₁ q₂ l^2 When one of the charges is doubled, let q₁' = 2q₁ and q₂' = q₂ . When the distance between them is halved, let l' = l 2 . The new force is: F' = 1 4 ₀ q₁' q₂' l'^2 F' = 1 4 ₀ 2q₁ q₂ ( l 2 )^2 F' = 1 4 ₀ 2q₁ q₂ l^2 4 F' = 8 ( 1 4 ₀ q₁ q₂ l^2 ) F' = 8F Thus, the magnitude of the force becomes 8 times the initial force, so n = 8 . Answer: 8

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