Thank you for reporting, we will resolve it shortly
Q.
A proton beam enters a magnetic field of $10^{-4}\,Wb\,m^{-2}$ normally. If the specific charge of the proton is $10^{11}\, C \,kg^{-1}$ and its velocity is $10^9 m\,s^{-1}$ then the radius of the ?circle decribed will be