10. A proton moves in a circular path at right angles to a uniform magnetic field of 0.75 T. Find the time taken for the proton to travel through one complete circle in the field. (5 marks) 9. An electron moving at 3.2 x 10 m/s passes very close to the end of a solenoid containing 3000 turns/m. If the electron experiences a deflecting force of 4.1 x 10- N, what must the current through the solenoid be