The Oscilloscope

An oscilloscope can be used to show the sizes of voltages and currents in both d.c. and a.c. circuits. This is what a typical oscilloscope looks like. A trace would be seen on the grid display.

D.C. Traces (Also seen in GCSE Physics 2)

If we connected a battery or cell to an oscilloscope, we would see a trace similar to the one shown here. The current of a d.c. supply is constant, this means the voltage is constant.

We see a straight line.

A.C. Traces (Also seen in GCSE Physics 2)

If we connect anything that draws power from the Mains to an oscilloscope we will see a similar trace to the one shown here. The current is constantly changing from maximum flow in one direction to maximum flow in the other direction; this means the voltage is doing the same.

We see a wave.