The Main Difference between Active and Passive Components

Electrical Technology

What is the Difference between Active and Passive Components?

The following basic explanatory post with examples shows the key differences between active and passive components and devices.

Active Components:

Those devices or components which require an external source to operate in a circuit are called active components.

For Example: Diode, Transistor, SCR etc.

Explanation: As we know, a diode is an active component. Therefore, it requires an external source to operate in a circuit.

This is because if we connect a diode in a circuit that is connected to a supply voltage, the diode will not conduct current (either in forward or reverse bias) until the voltage level reaches 0.3V (in the case of Germanium) or 0.7V (in the case of Silicon).

Passive Components:

Those devices or components which do not require an external source to operate in a circuit are called passive components.

For Example: Resistor, Capacitor, Inductor, etc.

Explanation: Passive components (such as resistors, capacitors, inductors, etc.) do not require an external source for their operation.

Unlike a diode, a resistor does not require 0.3V or 0.7V. That is, when we connect a resistor to the supply voltage, it starts to work and responds instantly in the circuit without needing additional and specific voltage like in the case of diodes. The same is true for inductors and capacitors.

Comparison between Active and Passive Elements and Devices

Active Component	Passive Component
Active Device transforms and injects power or energy into a circuit.	Passive Device utilizes power or energy into a circuit.
Examples: Diode, Transistor, SCR, ICs, DC generator, Current & Voltage sources etc.	Examples: Resistors, Capacitors, Inductors, Transformer, Motors etc.
Active element produces energy in the form of voltage or current.	Passive element stores energy in the form of voltage or current.
They have function and provide power gain (Amplifier).	They do not have function provide power gain.
It can control the flow of current.	It cannot control the flow of the current.
Active components require an external & conditional source to operate in the circuit.	Passive Components do not require any external source to operate in the circuit.
They have gain more than 1, so they can amplify the signal.	They have gain less than 1, so they can’t amplify the signal.
They are energy donor.	They are energy acceptor.
They lay in Linear category.	They lay in Non-Linear category.

In other words:

Active Components:

Those devices or components which produce energy in the form of voltage or current are called active components.

Examples: Diodes, Transistors, SCR, LED, Photodiode, Integrated Circuit, Operation Amplifier, Seven Segment Display, Battery, DC Generator, Current Source, Voltage Source, etc.

Passive Components:

Those devices or components which store or maintain energy in the form of voltage or current are known as passive components.

Examples: Resistor, Capacitor, Inductor, LDR, Variable Resistor, Thermistor, Switch, Motors, Transformer, etc.

In very Simple words;

Active Components: Energy Donor
Passive Components: Energy Acceptor

As a final touch, passive components fall into the linear category, and active components are in the non linear category.