MCQ
Two thin wire rings each having a radius $R$ are placed at a distance $d$ apart with their axes coinciding. The charges on the two rings are $+q$ and $-q.$ The potential difference between the centres of the two rings is
- AZero
- B$\frac{\mathrm{Q}}{4 \pi \varepsilon_0}\left[\frac{1}{\mathrm{R}}-\frac{1}{\sqrt{\mathrm{R}^2+\mathrm{d}^2}}\right]$
- C$\frac{\mathrm{QR}}{4 \pi \varepsilon_0 \mathrm{~d}^2}$
- ✓$\frac{\mathrm{Q}}{2 \pi \varepsilon_0}\left[\frac{1}{\mathrm{R}}-\frac{1}{\sqrt{\mathrm{R}^2+\mathrm{d}^2}}\right]$
