Resistor, Symbol of Resistor, Types of Resistors, Color Coding of Resistors (For CBSE, ICSE, IAS, NET, NRA 2022)

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Resistor is Ohm
  • It is defined as: “A passive electrical component with two terminals that are used for either limiting or regulating the flow of electric current in electrical circuits”
  • Main purpose of resistor is to reduce the current flow and to lower the voltage in any portion of the circuit.
  • It is made of copper wires which are coiled around a ceramic rod and the outer part of the resistor is coated with an insulating paint.
  • SI unit of resistor is Ohm.

Symbol of Resistor

Symbol of Resistor
  • Each resistor has one connection and two terminals.
  • The terminals of the resistor are each of the lines extending from the squiggle (or rectangle) .
  • Those are what connect to the rest of the circuit.
  • Resistor circuit symbols are usually enhanced with both a resistance value and a name.
  • The value, displayed in ohms, is obviously critical for both evaluating and constructing the circuit.

Types of Resistors

  • 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 resistor.
    • Linear resistor
    • Non-linear resistor

Linear Resistors

  • In linear resistors values change with change in applied temperature and voltage are known as linear resistors.
  • Fixed resistors: These resistors have a specific value and these values cannot be changed.
    • Carbon composition resistors
    • Wire wound resistors
    • Thin film resistors
    • Thick film resistors
  • Variable resistors: they do not have a specific value and the values can be changed with the help of dial, knob, and screw.
    • Potentiometers
    • Rheostats
    • Trimmers

Non-Linear Resistors

  • The resistor values change according to the temperature and voltage applied and is not dependent on Ohm՚s law.
    • Thermisters
    • Varisters
    • Photo resistors

What is Color Coding of Resistors?

  • It may not display the value outside but resistor color pattern through their resistance can be calculated.
  • PTH (plated-through-hole) resistors use a color-coding system (which really adds some flair to circuits) , and SMD (surface-mount-device) resistors have their own value-marking system.

Color Code of Resistors

Color Code of Resistors
ColorColor code
Black0
Brown1
Red2
Orange3
Yellow4
Green5
Blue6
Violet7
Grey8
White9

Tolerance of Resistor

Tolerance of Resistor
ColourTolerance
Brown
Red
Gold
Silver

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