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An electric dipole is placed on x - axis in proximity to a line charge of linear charge density 3 . 0 × 10 - 6 C m - 1 . Line charge is placed on z - axis and positive and negative charge of dipole is at a distance of 10 mm and 12 mm from the origin respectively. If total force of 4 N is exerted on the dipole, find out the amount of positive or negative charge of the dipole.

Options

  1. A815 . 1   nC
  2. B8 . 8   μ C
  3. C0 . 485   mC
  4. D4 . 44   μ C

Correct answer

D. 4 . 44   μ C

Step-by-step solution

r = 10   mm ,   x = 2 , F → q = 2 k λ r · q F → - q = 2 k λ r + x · q F → net = 2 k λ q · x r ( r + x ) 4 = 2 × 9 × 10 9 × 3 × 10 - 6 × q × 2   mm 10   mm . 12   mm ⇒ q = 4 . 44   μ C

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