What is Resistor?

What is Resistor?

The resistor is a passive electrical component that creates resistance in the flow of electric
current.

What is Resistance?

It is the property of a material that opposes the flow of electric current through it.

SI Unit of Resistance:

It is measured in Ohms(Ω) and denoted by ‘R’.

Symbols:

Types of Resistor:

Linear resistance:

Linear resistance refers to the behaviour of a resistor where its resistance remains constant regardless of the current flowing through it and whose characteristics remain constant when variables like voltage and temperature change.

Fixed Resistor:

A fixed resistor is one whose resistance value is set and cannot be changed or varied under normal operation.

Examples: Carbon Composition Resistor, Metal Oxide Resistor, Wire-Wound resistor, etc.

Variable Resistor:

A variable resistor is a resistor whose resistance value can be adjusted manually, allowing it to vary within a specific range.

Examples: Potentiometer, Rheostat, Trimmer, etc.

Non-linear resistance:

A nonlinear resistor is one that does not obey Ohm’s law. The non-linear resistor’s I-V characteristic is not a straight line.

Whose characteristics can be changed when variables like voltage and temperature change.

Applications of Resistor:

• Current Limiting: Protects components (e.g., LEDs) by restricting current flow.
• Voltage Division: Divides voltage into smaller values for sensors or circuits.
• Temperature Sensing: Used in thermistors to detect temperature changes.
• Biasing Transistors: Sets operating point in amplifiers and oscillators.
• Power Dissipation: Converts electrical energy into heat, protecting components.
• Surge Protection: Limits current surge to protect components.
• Timing Circuits: Controls timing in RC circuits for delays or oscillations.
• LED Brightness Control: Vary brightness by adjusting current with a potentiometer and many more.