# A disk rotating about a point on its circumference - 2

**Electricity and Magnetism**Level 4

Consider a uniformly charged circular disk of radius \(R\) having charge \(Q\) rotating about a fixed point on its circumference with an angular velocity \(\omega\) . The magnetic field created at this point due to the motion is \(k \times \dfrac{\mu_{0} Q \omega}{R}\). Find the value of \(k\) .