MCQ
The figure shows a nonconducting ring which has positive and negative charge non uniformly distributed on it such that the total charge is zero. Which of the following statements is true?
  • The potential at all the points on the axis will be zero.
  • B
    The electric field at all the points on the axis will be zero.
  • C
    The direction of electric field at all points on the axis will be along the axis.
  • D
    If the ring is placed inside a uniform external electric field then net torque and force acting on the ring would be zero.

Answer

Correct option: A.
The potential at all the points on the axis will be zero.
a
By symmetry potential due to negative part $=$(potential due to particle part). (Also every small charge is equidistant from axis)

$\therefore$ Potential at all potential axis is zero

Direction of field is perpendicular to axis and towards negative side

There will be a torque when placed in uniform field

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