WBJEE · Physics · Electrostatics
A point charge \(-q\) is carried from a point \(A\) to another point \(B\) on the axis of a charged ring of radius \(r\) carrying a charge \(+q\). If the point \(A\) is at a distance \(\frac{4}{3} r\) from the centre of the
ring and the point \(B\) is \(\frac{3}{4} r\) from the centre but
on the opposite side, what is the net work that need to be done for this?
- A \(-\frac{7}{5} \cdot \frac{q^{2}}{4 \pi \varepsilon_{0} r}\)
- B \(-\frac{1}{5} \cdot \frac{q^{2}}{4 \pi \varepsilon_{0} I}\)
- C \(\frac{7}{5} \cdot \frac{q^{2}}{4 \pi \varepsilon_{0} r}\)
- D \(\frac{1}{5} \cdot \frac{q^{2}}{4 \pi \varepsilon_{0} r}\)
Answer & Solution
Correct Answer
(B) \(-\frac{1}{5} \cdot \frac{q^{2}}{4 \pi \varepsilon_{0} I}\)
Step-by-step Solution
Detailed explanation
A charged circular ring of radius \(R\) is shown in figure. From the figure, \(d=\sqrt{x^{2}+r^{2}}\) \(\therefore\) Potential due to a uniform ring of positive charge \(q\) at point \(P\)…
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