Abstract
Abstract
We investigated the emf (V) induced with time (t) in a search coil due to an oscillating bar magnet along the axis of the coil using the IOLab device. Experimental data was simultaneously collected with the force sensor which tracked the oscillation of the magnet and the voltage sensor which gave real-time readings of the induced emf in the coil. For small amplitudes of oscillation, where the predominant interaction involved the top end of the magnet cutting through the plane of the coil, the V–t graph appeared sinusoidal. With increasing amplitudes of oscillation, the V–t graph started to lose its symmetry with an initial kink appearing within one half cycle and which eventually became an increasing hump as the amplitude of oscillation increased further due to the influence from the bottom end of the bar magnet which affected the overall rate of change of magnetic flux linkage through the coil. The data collected from the experiment was visualised using a novel parametric series of plots of induced emf (V) with force (F). We discussed various cases of the V–F parametric plot. Using a suitable Φ–h function and taking into consideration the rate of change of magnetic flux linkage with respect to displacement along the coil, we discussed how the emf induced changes with time with increasing amplitudes of oscillation.