A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit.
Resistors are used to provide a specific voltage for an active device such as a transistor. The main purpose of resistor is to reduce the current flow and to lower the voltage in any particular portion of the circuit. It is made of copper wires which are coiled around a ceramic rod & the outer part of the resistor is coated with an insulating paint. Resistors are available in different shapes and sizes. Common types that are available are through-hole and surface mount. A resistor might be static, standard resistor, special, or a pack of variable resistors. Resistors are used for controlling temperature and voltmeter & used in digital multi-meter, amplifiers, telecommunication,oscillators, modulators, demodulators, transmitters,flame detectors, burglar alarms, in photographic devices etc. These are classified into various types as follows - Chip SMD Resistors, Resistor Arrays, Resistor Kits, Thermistors, Through-Hole Resistors, Through-Hole Resistors,Wirewound Resistors.