1. The problem statement, all variables and given/known data A very thin beam of protons is injected at non-relativistic velocities in a circular particle accelerator of radius R. The mass m and the charge e of the proton are known. The initial current in the accelerator is I and the total number of particles is n. The magnetic flux through the beam circuit changes at a rate of p Wb/s, while the radius of the beam track remains unaltered. What is the value of the current after one turn of the particles? 2. Relevant equations I=q/t emf = dflux/dt R=(mv)/qB 3. The attempt at a solution I'm not exactly sure if I have understood the problem correctly. But here is what I have got so far: emf = dflux/dt = p Volts protons passing per second = I/e since flux = BA, and A is constant, then B is changing. B=(mv)/Rq, so v of the particles must be changing. We are just learning about magnetic fields in class and I don't know how to put all the information together in this problems. I hope someone can at least point me in the right direction. Thanks!