Theory - 8 :- Color Coding Chart And Calculating Resistance Value

 

The Resistor: A Basic Introduction

• A resistor is an electronic component that limits current flow in a circuit. When a resistor makes a connection with a circuit, the resistor’s resistance is fixed through two points that restrict current in the connected components of the circuit.
• Suppose your circuit has a fixed resistor with a constant resistance value. while the variable resistor is called a potentiometer.
• An ideal resistor shows linear operation in a circuit; this resistor has a direct proportional relation between the current flowing in the circuit and the applied voltage.
• The primary purpose of a variable resistor is to provide voltage at different levels.
• Each resistor comes with a certain value of resistance that determines whether the resistor is applicable for our circuit or not.
• Different resistor color codes exist on resistors that help to find the resistance value of certain resistors.

Key Characteristics and Types

• Fixed Resistor: This is a resistor with a constant resistance value. No matter what changes in the circuit, its resistance stays the same.

• Variable Resistor (Potentiometer): This type of resistor allows you to change its resistance value. They are often used as knobs for controlling volume on a speaker or brightness on a light, as they can provide different voltage levels.

• Ideal Resistor: An ideal resistor has a perfectly linear relationship between the voltage across it and the current flowing through it. This relationship is defined by Ohm's Law (

  $$V=IR$$, where V is voltage, I is current, and R is resistance.

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What is a resistor color code?

• Perhaps you’ve noticed that a resistor is a small component, making it challenging to print any numbers or letters on it, or the print is not easily visible.
• To easily understand resistance values in the 1920 Radio Manufacturers Association (RMA) resistor color code system.
• There are different colored bands on the resistor that help to find the resistance of the resistor; each colored band defines a certain decimal value.
• These color codes help us find resistance values through an easy understanding of these colors. Either the resistor is connected with the circuit or also damaged due to a short circuit.
• The resistor color coding method is used for carbon film resistors, metallic oxide film resistors, etc.
• To find the resistance value, we read each band’s color codes one by one from the left side and the tolerance band on the right side.
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• Resistor Color Code Chart 

  

  
  

  4-Band Resistor value

  Band	Meaning
  1st	1st Digit
  2nd	2nd Digit
  3rd	Multiplier
  4th	Tolerance

  Example:
  Red – Violet – Orange – Gold
   2 – 7 × 1,000 = 27,000 Ω (27kΩ) ±5%

  
  

  

  
  

• 5-Band Resistor

  Band	Meaning
  1st	1st Digit
  2nd	2nd Digit
  3rd	3rd Digit
  4th	Multiplier
  5th	Tolerance

  Example:
  Brown – Green – Black – Red – Brown
  1 – 5 – 0 × 100 = 15,000 Ω (15kΩ) ±1%