A resistor is a specialized electrical component that provides resistance as a circuit element. Resistors are passive, which means they are not affected by the current they carry.Continue Reading
Resistors have two primary functions within a circuit:
Resistors are usually made of metal or carbon wire. They are designed to keep a constant value when in use and produce heat instead of light when used inside an electrical component. As the circuit works, resistors dissipate heat, which is not used. On the other hand, the metal portion of a light bulb is a type of resistor that does emit light.
There are three types of resistors:
Fixed resistors are the most common. They can be found inside many different types of electronic components and serve to protect them from too much current flow.
Traditional variable resistors are continually altered as they work. A common type of variable resistor is found in the volume control on a radio. Another type of variable resistor is called a potentiometer, or a pot. Pots are usually small and work by having their resistance control adjusted once and fixed, often with a screwdriver.
Two common types of special resistors include light-dependent resistors, which change resistance as light levels change. Similarly, thermistors change resistance as the temperature changes.Learn more about Electrical
A linear resistor is a resistor whose resistance does not change with the variation of current flowing through it. In other words, the current is always directly proportional to the voltage applied across it.Full Answer >
Rheostat switches are electrical switches that contain a variable resistor, which allows them to finely adjust the amount of current passed along the attached circuit. Rheostat switches were once commonly used as dimmers for electric lights.Full Answer >
A rheostat is a variable resistor that is used to alter the amount of voltage or current in a circuit, according to HowStuffWorks. Rheostats make possible functions of electronics such as light dimmers and volume dials.Full Answer >
An ohmmeter measures the electrical resistance of a circuit by sending a small charge from one terminal into the circuit, receiving the charge on its opposite terminal and calculating the loss. The ohmmeter works according to Ohm's Law, which expresses the resistance as a ratio of voltage to current. Ohmmeters are always used with the only source of voltage being the meter's battery.Full Answer >