A trolley fitted with a strong magnet moves down a ramp at a steady speed. As it goes through a coil, as shown, an electromotive force (e.m.f.) is induced in the coil. A graph showing e.m.f. against time is drawn. The investigation is carried out again using different coils and a steeper ramp. On the steeper ramp, the trolley travels at a larger steady speed. Which graph is obtained with the coil having the fewest turns and the steepest ramp? Every graph is on the same scale.
Physics 5054 · O Level · Electromagnetic induction