The following figure shows a conducting disc rotating about its axis in a perpendicular magnetic field $B$. The resistor of resistance $R$ is connected between the centre and the rim. The current in the resistor is (The radius of the disc is $5.0\mathrm{ }\mathrm{c}\mathrm{m}$, angular speed $\mathrm{\omega }=10\mathrm{ }\mathrm{r}\mathrm{a}\mathrm{d} {\mathrm{s}}^{-1},\mathrm{ }B=0.40\mathrm{ }\mathrm{T}$ and $R=\mathrm{10 }\mathrm{\Omega }$)