Types of Resistors and Their Functions

Different types of resistors with pictures, symbols,function and uses

Resistor is an electrical component that regulates or limit the flow of electrical current in a electronic circuit. Resistors can also be used to provide a specific voltage to active a device such as a transistor. It is most commonly used components in all types of electronics devices.


Types of resistors

There are two types of resistors mainly and further divided into more types according to their functions.

  1. Variable Resistor
  2. Fixed Resistor

What is a variable resistor?

A resistor which value can be adjusted is called variable resistor. A variable resistance is useful when we do not know what value of resistor will be required in a circuit. By using pots as an adjustable resistor we can set the right value while circuit is working.

Types of variable Resistors?

Different types of variable resistors are as follows.


Potentiometer is an ordinary variable resistor. A potentiometer has three terminal in which the resistance is manually varied to control the flow of low power current. The potentiometer consists of three terminals. we can increase and decrease the resistance of potentiometer to controls the flow of electric current by rotating the nob.



A rheostat is also a variable resistor which is used to control current.These variable resistors are able to change the resistance in a circuit without interruption. The structure of these resistors are almost same like potentiometer. Only two terminals are used even if these variable resistors have three terminals. Rheostats are often used as power control devices, for example to control light intensity, to control the speed of motors, heaters and ovens etc.

Types of Rheostat


Presets are the small versions of standard variable resistors.They are designed to be mounted on circuit boards and adjusted only when the circuit is built however its value can be adjusted. Presets are available in vertical and horizontal shape and style. Different shapes of Preset is showed in the given below figure.