what is resistor

 register is an electrical component used to reduce the electrical current in a circuit. The register is measured in units of ohms and has two terminals. 

The register is constructed using carbon or metal wire. There are mainly two types of registers, fixed value registers, variable registers. 

Fixed value resistors, 

The value of fixed value register is always fixed, its value cannot be increased or decreased whereas the value of variable register can be increased or decreased. 

Resistor Color Code Calculator

Select the colors of the bands on your resistor:

Band 1: Black Brown Red Yellow Green Blue Violet Grey White Band 2: Black Brown Red Oregon Yellow Green Blue Violet Grey White Band 3: Black Brown Red Orange Yellow Green Blue Violet Grey White Band 4: Gold Silver

The value of the fixed value register is indicated above it in the form of a color band. It is made of electro-resistant material. Fixed value registers also belong to the following categories. 

Flameproof Mattel oxide resistors,

Flameproof Mattel oxide resistors is produced by coating a thin layer of tin chloride on a glass rod which is shown in the picture below. 

Carbon film resistors,

Carbon Film Register is manufactured from high grade ceramic material.  Which is shown in the picture below.

Wirewound resistors;

Wirewound resistors are manufactured by winding tungsten, nichrome or nickel wire over an insulator rod. The value of this resistor depends on the length of the wire.

                 

Variable resistors;

The value of the variable resistor is not always fixed, its value can be increased or decreased as per the requirement.  Variable resistor is used to increase or decrease the volume in radio, TV and music system etc. It is of three types.  

Potentiometer variable resistors

The potentiometer variable resistor shown in the following figure is used to control the voltage level in any electrical circuit.  By rotating the knob in it, you can set it to the value as per the requirement.  

trimmer or preset is a variable resistor that is embedded in a PCB board along with other components and requires a screwdriver to change its value.