Six point charges,each of magnitude $q$,are arranged in different manners as shown in the image. In each case,a point $M$ and a line $PQ$ passing through $M$ are shown. Let $E$ be the electric field and $V$ be the electric potential at $M$ (potential at infinity is zero) due to the given charge distribution when it is at rest. Now,the whole system is set into rotation with a constant angular velocity about the line $PQ$. Let $B$ be the magnetic field at $M$ and $\mu$ be the magnetic moment of the system in this condition. Assume each rotating charge to be equivalent to a steady current. Match the conditions in Column $I$ with the configurations in Column $II$.
Column $I$Column $II$
$(A)$ $E=0$$(p)$ Charges at corners of a regular hexagon. $M$ is the centre. $PQ$ is perpendicular to the plane.
$(B)$ $V \neq 0$$(q)$ Charges on a line perpendicular to $PQ$ at equal intervals. $M$ is the mid-point.
$(C)$ $B=0$$(r)$ Charges on two coplanar concentric rings. $M$ is the common centre. $PQ$ is perpendicular to the plane.
$(D)$ $\mu \neq 0$$(s)$ Charges at corners and mid-points of a rectangle. $M$ is the centre. $PQ$ is parallel to the longer sides.
$(t)$ Charges on two coplanar,identical rings. $M$ is the mid-point between centres. $PQ$ is perpendicular to the line joining centres.

  • A
    $(A) \rightarrow p, r, s; (B) \rightarrow r, s; (C) \rightarrow p, q, t; (D) \rightarrow r, s$
  • B
    $(A) \rightarrow p, t, s; (B) \rightarrow r, p; (C) \rightarrow r, q, t; (D) \rightarrow r, q$
  • C
    $(A) \rightarrow q, r, s; (B) \rightarrow r, p; (C) \rightarrow t, q, t; (D) \rightarrow r, t$
  • D
    $(A) \rightarrow t, q, p; (B) \rightarrow p, q; (C) \rightarrow r, q, s; (D) \rightarrow r, s$

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