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

Tolerance of Resistor

Tolerance of Resistor

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