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Paragraph: A uniform disc of mass m and radius R is made up of two halves, one half has charge +Q uniformly distributed over it & another half has charge -Q uniformly distributed over it. This system is kept on rough surface in a uniform horizonal field E in a way so that line of seperation become parallel to field, system is released from rest, at t =0 as shown in figure. Question: Torque of the electrostatic force

Options

  1. A4 QE 9 mg
  2. B8 QE 9 mg
  3. C16 QE 9 mg
  4. D2 QE 3 mg

Correct answer

C. 16 QE 9 mg

Step-by-step solution

p = Q d = Q 8 R 3 j ; = p E = pE k ;| |= 8 QRE 3

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