Charge of electron/proton = 1.6*10^-19 coulombs Mass of proton m1 = 1.67*10^-27 kg Mass of electron m2 = 9.109 × 10-31 kg Given :- Speed v = 2.64*10^7 m/s Radius R = 160 m R = m*v / (q*B) q*B = m*v / R B = m*v / (R*q) For proton B = 1.67*10^-27 * 2.64*10^7 / (160 * 1.6*10^-19) B = 1.722 *10^-3 Now for electron B = 9.109*10^-31 * 2.64*10^7 / (160 * 1.6*10^-19) B = 9.39 *10^-7