The larger the number the smaller the diameter of the wire. So, the diameter of a number 12 wire is less than the diameter of a number 6 wire.

An inductor is coiled wire that stores electric energy in the form of magnetic energy and resists changes in the electric current flowing through it. If current is increasing, the inductor produces a voltage that slows the increase and, if current is decreasing, the magnetic energy in the coil opposes the decrease to keep the current flowing longer. In contrast to capacitors, inductors allow DC to pass easily but resist the flow of AC.

Connecting the 10 batteries in series multiplies their voltage while keeping their current the same yielding a 90V 25A configuration. Connecting the 10 batteries in parallel multiplies their current while keeping their voltage the same yieleding a 9V 250A configuration. Using a series-parallel connection, 5 batteries can be connected in series and 5 can be connected in parallel resulting in a 45V 125A configuration.

Current is the rate of flow of electrons per unit time and is measured in amperes (A). An ammeter is used to measure the electric current in a circuit.

A diode allows current to pass easily in one direction and blocks current in the other direction. Diodes are commonly used for rectification which is the conversion of alternating current (AC) into direct current (DC). Because a diode only allows current flow in one direction, it will pass either the upper or lower half of AC waves (half-wave rectification) creating pulsating DC. Multiple diodes can be connected together to utilize both halves of the AC signal in full-wave rectification.