1) A horizontal metal rod of 1.5m long is aligned in and East-West direction and dropped from rest from the top of a high building. Calculate the e.m.f. induced across the falling rod 2.5s after release. The horizontal component of Earths magnetic field is 2x10^5 T. Surely you need the area perpendicular to field lines, which would be the area of a circle. so you need the radius of the rod? 2) Explain why positive paint drops are attracted to the metal object. This is about an electrostatic paint sprayer, and the metal object is earthed.