MCQ
A thin ring of $10\, cm$ radius carries a uniformly distributed charge. The ring rotates at a constant angular speed of $40\,\pi \,rad\,{s^{ - 1}}$ about its axis, perpendicular to its plane. If the magnetic field at its centre is $3.8 \times {10^{ - 9}}\,T$, then the charge carried by the ring is close to $\left( {{\mu _0} = 4\pi \times {{10}^{ - 7}}\,N/{A^2}} \right)$
- A$2 \times {10^{ - 6}}\,C$
- B$7 \times {10^{ - 6}}\,C$
- C$4 \times {10^{ - 5}}\,C$
- ✓$3 \times {10^{ - 5}}\,C$
