Additional Materials Reading 1 Points] DETAILS OSUNIPHYS1 28.3.WA.011. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER A proton enters a region of constant magnetic field, perpendicular to the field and after being accelerated from rest by an electric field through an electrical potential difference of -300 V. Determine the magnitude of the magnetic field, if the proton travels in a circular path with a radius of 27 cm. mT Additional Materials Reading