A Differenliatlng Circuit. The current in a resistanceless inductor is caused to vary with time as shown in the graph of Fig. 30.19.(a) Sketch the pattern that would be observed on the screen of an oscilloscope connected to the terminals of the inducror. (The oscilloscope spot sweeps horizontally across the screen at a constant speed. and its vertical deflection is proportional to the potential difference between the inductor terminals.)(b) Explain why a circuit with an inductor can be described as a "differentiatingcircuit."