Measuring electricity is really easy—we're all familiar with electrical units like volts, amps, and watts (and most of us have seen moving-coil meters in one form or another). Measuring magnetism is a little bit harder. Ask most people how to measure the strength of a magnetic field (...
The voltage, V, in volts across a circuit is given by Ohm's Law: V = IR, where I is the current (in amps) flowing through the circuit and R is the resistance (in ohms). If we place two circuits with In a simple electric circuit...