A wheel with 10 metallic spokes each 0.3 m long is rotated with a
speed of 120 rev/min in a plane normal to the horizontal component
of earth’s magnetic field HE at a place. If HE = 0.4 G at the place, what
is the induced emf between the axle and the rim of the wheel? Note
that 1 G = 10–4 T.
