*Active Components:
Electronic components that require external power to work and can amplify signals.
Example: Transistor
*Passive Components:
Electronic components that do not require external power and cannot amplify signals.
Example: Resistor
*Specifications of Capacitor:
Capacitance
Working voltage
Tolerance
Leakage current
*Specifications of Inductor:
Inductance
Current rating
Resistance
Core material
*compare active & passive components
Active Components Passive Components
1.Require external power 1.Do not require external power
2.Can amplify signals 2. Cannot amplify signals
3.Control current flow 3.Store or dissipate energy
4.More complex in operation 4.Simple in operation
5.Used for switching and amplification 5.Used for filtering and energy storage
6.Example: Transistor 6.Example: Resistor
*Define amplitude,frequency,phase,wavelength of signal
Amplitude:
Maximum height or value of a signal from its zero position.Frequency:
Number of cycles completed by a signal in one second.
Unit: Hertz (Hz)Phase:
Angular position of a waveform with respect to a reference waveform.Wavelength:
Distance between two consecutive similar points of a wave.
Unit: Meter (m)
*Drow symbols of resister,capacitor,led,photodiode,zenordiode,pn junction diode
1) Resistor
──/\/\/\/──
2) Capacitor
──| |──
3) LED
↗ ↗
──|>|──
4) Photodiode
↘ ↘
──|<|──
5) Zener Diode
──|<|──
┐ ┘
6) PN Junction Diode
──|>|──
*LED
LED (Light Emitting Diode):
A semiconductor device that emits light when electric current passes through it.
*Explain working priciple of zenr diode
Working Principle of Zener Diode:
A Zener diode works in reverse bias condition. When the reverse voltage reaches the Zener breakdown voltage, the diode starts conducting current without damage. It maintains a nearly constant voltage across its terminals. Therefore, it is mainly used for voltage regulation and protection circuits.
*drow & describe working principle of LED
Symbol of LED:
↗ ↗
───|>|───
Working Principle of LED:
LED works on the principle of electroluminescence. When the LED is connected in forward bias, current flows through the PN junction. Electrons and holes recombine and release energy in the form of light. The color of light depends on the semiconductor material used.
*What is need of biasing a transister ? list types of transister.
Need of Biasing a Transistor:
Biasing is required to set the proper operating point of a transistor for correct amplification and stable operation.
Types of Transistor:
NPN Transistor
PNP Transistor
*List different configuration of BJT
Different Configurations of BJT:
Common Base (CB) Configuration
Common Emitter (CE) Configuration
Common Collector (CC) Configuration
Fixed Bias Configuration
Collector to Base Bias Configuration
Voltage Divider Bias Configuration
*define alpha & beta of transister
Alpha (α) of Transistor:
Alpha is the ratio of collector current to emitter current in CB configuration.
Beta (β) of Transistor:
Beta is the ratio of collector current to base current in CE configuration.
*compare CE,CB,CC
Parameter CE Configuration CB Configuration CC Configuration
Input terminal Base Emitter Base
Output terminal Collector Collector Emitter
Current gain High Low High
Voltage gain High High Low
Power gain High Medium Medium
Phase difference 180° 0° 0°
*State barkhausen criteria
Barkhausen Criteria (4 Marks):
The Barkhausen criterion states the conditions required for sustained oscillations in an electronic oscillator.
The total phase shift around the feedback loop must be 0° or 360°.
The feedback must be positive.
The loop gain must be equal to unity.
A\beta = 1
Where,
( A ) = Amplifier gain
( \beta ) = Feedback factor
If these conditions are satisfied, continuous oscillations are produced.
*Difference between positive and negative feedback
Positive Feedback Negative Feedback
Feedback signal is in phase Feedback signal is out of input signal phase with input signal
Increases overall gain Decreases overall gain
Reduces stability Improves stability
Used in oscillators Used in amplifiers
Increases distortion and noise Reduces distortion and noise
Example: Oscillator circuit Example: Audio amplifier
*State the output voltages of IC 7805 and IC 7912
1. IC 7805 → Output voltage = +5 V
2. IC 7912 → Output voltage = −12 V
*what is switch mode pwer supply
Switch Mode Power Supply (SMPS):
SMPS is an electronic power supply that converts electrical power efficiently using high-frequency switching devices like transistors.
Working:
AC input is converted into DC.
DC is switched at high frequency.
Transformer and filter circuits convert it to required DC output.
Advantages:
High efficiency
Small size and light weight
Applications:
Computers
Mobile chargers and TVs