What Does a Resistor Do?

A resistor is a little package of resistance used to reduce the current in an electric circuit by a certain amount. It is a small component that has connectors on both sides that allow it to connect to a circuit.

Resistance is defined as the ease in which electricity flows through a material. Resistance is measured in ohms, and resistors, which limit or lower the amount of resistance, are used in all types of electric circuits. A wire-wound resistor has a ceramic rod running through it with a copper wire wrapped around the outside. The amount of resistance provided depends on the number of turns of the copper on the resistor and the thickness of the copper.

Cheaper resistors are called carbon-film resistors and are designed for lower power circuits. In these resistors, the copper winding is replaced by a spiral pattern of carbon.

Resistors have bands of colors on them to indicate the amount of resistance that the resistor provides. Most resistors have three bands of color and then a space and another band of color. The first two bands indicate the first two digits of the resistance, and the third is a digital multiplier that is multiplied by the value of the first two bands. The fourth color band is a decimal multiplier that is called the tolerance and tells the accuracy of the first three numbers.