Faraday’s law of induction deals with how a magnetic flux induces an emf in a circuit. recall that magnetic flux depends on magnetic field strength and the effective area the field is passing through. we’ll start our investigation by looking at the field strength around a bar magnet. position the magnet around the coil so that the region labeled a in the figure below is inside the coil. move the magnet slowly back and forth and observe the effect on the brightness of the bulb and the needle of the voltmeter. repeat the same process for the other two regions.