Identification of Various Active and Passive Electronic Components in a Given Circuit

Experiment No.: 10

Experiment Name:

Identification of Various Active and Passive Electronic Components in a Given Circuit


To identify various active and passive electronic components in a given circuit.


1. Active Components : An active component is an electronic component which supplies energy to a circuit.

Common examples of active components are:

  • Voltage sources
  • Current sources
  • Generators (such as alternators and DC generators)
  • All different types of transistors (such as bipolar junction transistors, MOSFETS, FETs, and JFET)
  • Diodes (such as Zener diodes, photodiodes, Schottky diodes, and LEDs)

2. Passive Components: A passive component is an electronic component which can only receive energy, which it can either dissipate, absorb or store it in an electric field or a magnetic field. Passive elements do not need any form of electrical power to operate. As the name ‘passive’ suggests – passive devices do not provide gain or amplification. Passive components cannot amplify, oscillate, or generate an electrical signal.

Common examples of passive components are:

  • Resistors
  • Inductors
  • Capacitors
  • Transformers

Different Elements Identified:

Sl. No.Name of the ElementsFigure of the ComponentSymbolComponent TypeFunctionApplicationNo. of Terminals
1.Resistorresistorr symbolPassiveIt resist the flow of currentShunt, multiplier, current controller, 2
2.POT (Potentiometer)potpot symbolPassiveIt works as a variable resistorControl volume, brightness, colour3
3.LDR (Light Dependent Resistor)ldrLDR SYMBOLPassiveIt is used where there is a need to sense the presence and absence of light is necessary.Alarm clocks, street lights, light intensity meters, burglar alarm circuits2
4.Inductorinductorind symPassiveIt helps to store energy in the form of magnetic energy when electric current flows through itChoking, blocking, attenuating, or filtering/smoothing high frequency noise in electrical circuits2
5.Polarised Capacitorpol capPOL CAP SYMPassiveIt passes AC and block DCto filter power supplies in ac to dc rectifier circuit2
6.Non Polarised Capacitornon pol capCAP SYMPassiveIt has no implicit polarity – it can be connected either way in a circuitused in circuits of coupling, decoupling, feedback, compensation, and oscillation2
7.PN Junction DiodediodeDIODE SYMPassiveIt is used to remove negative signals from AC currentRectifier circuit, isolating signals from a supply, and mixing signals2
8.Zener DiodeZEN DIODE ZEN SYMBOLActiveIt can act as a steady output voltage for a load connected in parallel with itVoltage regulation, as reference elements, surge suppressors, switching applications and clipper circuits2
9.LED (Light Emitting Diode)LEDLED SYMBOLPassiveIt is a specialised type of diode as they have very similar electrical characteristics to a PN junction diodeModern illumination, indicator, display2
10.PNP TransistorPNPPNP SYMActiveIt helps to control current flow in heavy applicationsAmplification circuits3
11.NPN TransistorNPNNPN SYMActiveIt is used to amplify weak signalsSwitching applications, amplification circuits3
12.FET (Field Effect Transistor)FETFET SYMActiveIt is a voltage controlled device due to this it is used in operational amplifier as voltage variable resistors.Input amplifiers in devices i.e. voltmeters, oscilloscopes, and other measuring devices3
13.MOSFET (Metal Oxide Semiconductor Field Effect Transistor)MOSFETMOSFET SYMActiveIt has an insulated gate, whose voltage determines the conductivity of the device. automotive electronics, particularly as switching devices in electronic control units, and as power converters in modern electric vehicles3
14.SCR (Silicon Controlled Rectifier)SCRSCR  SYMActiveIt is essentially a switch with no moving parts. It consists of a semiconductive path and what is called a bridge. used in devices where the control of high power, possibly coupled with high voltage, is demanded3
15.TransformerTRANSFORMERTRANSFORMER SYMPassiveIt is a static device which transfer electric power from one circuit to another without changing it’s frequency.To step up and step down the voltage and current 4 or 5 (in case of centre tapped transformer)

Remarks: The aforesaid elements are identified successfully in a given circuit.

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