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A small uncharged conducting sphere is placed in contact with an identical sphere but having 4 10⁻⁸ C charge and then removed to a distance such that the force of repulsion between them is 9 10⁻³ ~N . The distance between them is (Take 1 4 _ o as 9 10^9 in SI units)

Options

  1. A3 cm
  2. B2 cm
  3. C4 cm
  4. D1 cm

Correct answer

B. 2 cm

Step-by-step solution

aligned & F = k ( 2 ) ( 2 ) r ^2 & 9 10⁻³= 9 10^9 (4 10⁻⁸ ) 4 10⁻⁸ 4 r ^2 & r ^2= 9 10^9 16 10⁻¹⁶ 4 9 10⁻³ =4 10⁻⁴ & r =2 10⁻² ~m 2 ~cm aligned

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