Resistors

1. Overview

A resistor is a passive two-terminal electronic component that implements electrical resistance as a circuit element.

resistors

Resistor symbol

resistor symbol

2. Features

  • Measurement: measured in ohms (Ω).
  • Tolerance: how much the actual resistance can vary from the stated value (e.g., ±1%, ±5% even ±20%)
  • Temperature: resistance changes with temperature (measured in ppm/°C).
  • Physical Size: larger resistors typically handle more power.
  • Fixed or Variable: Can be either fixed (standard resistors) or adjustable (potentiometers, rheostats).

4. How to Use

4.1. Identify the resistor value

  • Read the color bands or use a multimeter.
  • Value is given in Ohms (Ω).

resistor color code

4.2. Choose the right resistor

  • Resistance needed (Ohm’s Law: R = V/I)
  • Power rating (typically ¼ W or higher)
  • Tolerance (how much variation from the value is allowed)

4.3. Connect it correctly

  • Resistors are non-polarized (no + or - ends).
  • Place it in series (resistor is placed in line with a component)to limit current. => the total resistence is the sum of all resistors
  • Place it in parallel (resistor is placed alongside another component) to divide voltage or current. => resistence is less than the smallest resistor.
  • Place it in compound to get a combination of series and parallel. => resistence is determined by the interaction of series and parallel arrangements.

4.4. Connect it correctly

  • use a multimeter to check the voltage drop accross resistror ad current through the circuit
  • Ensure it’s not overheating (if it is then choose a higher wattage).

4.5 Solder it or breadboard

  • on breadboard, push the resistor through the holes.
  • on PCB, solder the leads into the designed pads.

5. Video Explanation

video coming soon