1. The problem statement, all variables and given/known data Diagrams (a) to (c) show a magnetic field of flux density 0.2 T directed perpendicularly into the paper. In each of (a) and (b) a conductor of length 0.3 m is entirely within the field and is carrying a current of 4 A in the plane of the paper. In (c) an electron is moving in the plane of the paper at 2 * 106 m/s. Copy the diagrams and show the direction of the force in each case. Also find the magnitude of the forces. (Charge on the electron = 1.6 * 10-19 C.) Images: Answers: 2. The attempt at a solution F = BIL sin θ F = BQv sin θ (a-b) F = 0.2 * 4 * 0.3 * sin 90 = 0.24 N (c) F = 0.2 * 1.6 * 10-19 * 2 * 106 * sin 90 = 6.4 * 10-14 N The (a-b) graphs we get using the Fleming's left-hand rule. For (c), however, I get the force directed in the opposite direction (to north-east, not south-west). I think this is because (in constrast to (a-b), where there was current in each case and not particle) the particle is directed downwards and thus is negatively charged, so we need to change the middle finger from south-east to north-west. But I'm not sure about that. Any ideas on (c) graph please?