Unit 1

1) What is Active & Passive Electronics Components? List out Active components with symbol. List out Passive component with symbol.

Active and passive electronic components are two broad categories of components used in electronic circuits.

Active components are devices that can control the flow of electricity. They require a power source to function and can amplify, rectify, or switch electronic signals. Examples of active components include transistors, integrated circuits, and operational amplifiers. Here are some common active components along with their symbols:

1. Transistor (NPN):
2. Transistor (PNP):
3. Operational Amplifier (Op-Amp):

Passive components, on the other hand, do not require an external power source to function. They do not amplify or control the flow of electricity but instead, they store energy or dissipate it. Examples of passive components include resistors, capacitors, and inductors. Here are some common passive components along with their symbols:

1. Resistor:
2. Capacitor:
3. Inductor:

These symbols are commonly used in circuit diagrams to represent the corresponding components.

2) Explain working/Function of Active Components with symbol.

Active components are electronic devices that can amplify, rectify, or switch electronic signals. They require an external power source to function. Here’s an explanation of the working/function of some common active components along with their symbols:

1. Transistor (NPN and PNP):
   • Function: Transistors are semiconductor devices that can amplify or switch electronic signals and electrical power. In an NPN transistor, a small current at the base terminal controls a larger current between the collector and emitter terminals. In a PNP transistor, the current flows in the opposite direction.
   • Working: When a small current flows into the base terminal of the transistor, it allows a larger current to flow between the collector and emitter terminals. This amplification is the basic principle behind how transistors work in electronic circuits.
2. Operational Amplifier (Op-Amp):
   • Function: Operational amplifiers are versatile, high-gain electronic voltage amplifiers. They are used in a wide variety of applications, including signal conditioning, filtering, and mathematical operations.
   • Working: Op-amps amplify the difference in voltage between the two input terminals (inverting and non-inverting). The output voltage is the amplified difference, and the amplification factor is determined by the op-amp’s characteristics and external components in the circuit.

These active components play crucial roles in electronic circuits, enabling a wide range of functionalities, from simple signal amplification to complex signal processing.

3) Explain working/Function of Passive Components with symbol.

Passive components are electronic components that do not require an external power source to function. They store, dissipate, or control the flow of electrical energy. Here’s an explanation of the working/function of some common passive components along with their symbols:

1. Resistor:
   • Function: Resistors limit or control the flow of electrical current in a circuit. They are used to reduce voltage levels, divide voltages, limit current, and adjust signal levels.
   • Working: A resistor’s resistance is determined by its material and dimensions. When a voltage is applied across a resistor, it creates a current flow proportional to the voltage and inversely proportional to the resistance, as per Ohm’s Law (V = IR).
2. Capacitor:
   • Function: Capacitors store and release electrical energy. They are used to filter signals, store energy, smooth voltage fluctuations, and block DC while allowing AC to pass.
   • Working: A capacitor consists of two conductive plates separated by an insulating material (dielectric). When a voltage is applied, it charges the capacitor by storing opposite charges on the plates. The amount of charge stored is proportional to the applied voltage.
3. Inductor:
   • Function: Inductors store energy in a magnetic field when current flows through them. They are used to filter signals, store energy, and create reactance in AC circuits.
   • Working: An inductor’s ability to store energy in a magnetic field is proportional to the current flowing through it. When the current changes, the magnetic field changes, inducing a voltage in the inductor that opposes the change in current, according to Faraday’s law of electromagnetic induction.

These passive components are essential building blocks of electronic circuits, providing various functions that are fundamental to the operation of electronic devices.

4) What is IC ?How to identify Pin out of ICs?

An Integrated Circuit (IC) is a small electronic device made out of a semiconductor material, such as silicon. It consists of many interconnected electronic components such as transistors, resistors, capacitors, and diodes, all fabricated onto a single chip.

To identify the pinout of an IC, you can follow these general steps:

1. Identify the IC: Look for any markings or labels on the IC that can help identify it. These markings usually include a part number, manufacturer logo, and possibly other information like date code or country of origin.
2. Refer to Datasheet: Search for the datasheet of the identified IC online. The datasheet contains detailed information about the IC, including its pinout.
3. Locate Pin 1: Once you have the datasheet, locate Pin 1 of the IC. Pin 1 is typically indicated by a dot, notch, or a beveled edge on one side of the IC. Sometimes, the datasheet may also have a pinout diagram indicating the location of Pin 1.
4. Identify Other Pins: Once you have identified Pin 1, you can usually count the pins in a particular order (e.g., counter-clockwise or clockwise) around the IC to determine the function of each pin. The datasheet will provide a pinout diagram that shows the function of each pin.
5. Check for Key Features: Some ICs have key features, such as a notch or a different pin shape, to indicate specific pins, such as power supply pins (VCC and GND).
6. Use a Multimeter: If the markings on the IC are not clear or if you cannot find the datasheet, you can use a multimeter in continuity mode to identify the pins. Connect one probe to a known pin (e.g., Pin 1) and then touch the other probe to each pin until you hear a beep, indicating continuity.

It’s important to be cautious when handling ICs, as they are sensitive to static electricity and mishandling can damage them.

5) What is Breadboard ? Define specification of Bread Board. How are the holes connected in Bread Board?

A breadboard is a reusable solderless device used to build and test electronic circuits. It allows you to quickly prototype circuits without the need for soldering. Breadboards are commonly used in electronics labs, classrooms, and by hobbyists.

Specifications of a Breadboard:

1. Dimensions: Breadboards come in various sizes, but a standard size is about 8.5 cm x 5.5 cm (small size) or 16.5 cm x 5.5 cm (large size).
2. Holes: Breadboards have a grid of holes into which electronic components and wires can be inserted. The holes are typically spaced at a pitch of 2.54 mm (0.1 inches).
3. Rows and Columns: Breadboards are typically divided into two sections: the terminal strips and the bus strips. The terminal strips are arranged in rows, labeled from A to J and columns labeled from 1 to 30 (or more). The bus strips run along the sides of the breadboard.
4. Connection Mechanism: Inside the breadboard, the holes are connected in a specific pattern. The terminal strips are connected horizontally in rows, while the bus strips are connected vertically in columns. The rows and columns are usually connected internally in a specific pattern, which can vary slightly depending on the manufacturer.

Connection Mechanism in Breadboard:

1. Terminal Strips: The holes in each row of the terminal strips are electrically connected internally. This allows you to insert a component (such as a resistor or LED) and connect it to other components in the same row using jumper wires.
2. Bus Strips: The bus strips are connected vertically in columns. The columns are usually split into two sections (left and right) by a gap in the middle. The left and right sections are not connected internally, allowing you to create separate power rails (e.g., VCC and GND) or signal lines.

When you insert a component or wire into a hole in the breadboard, it makes electrical contact with the metal clip inside the hole, creating a connection. This allows you to quickly build and test circuits without the need for soldering.

6) Write the correct value of following resister for four band resistor :

• Brown Black Red No color
• Blue Green Orange Silver
• While Blue Yellow Gold

To determine the resistance value of a four-band resistor, you need to follow the standard resistor color code. The color bands represent digits or multipliers that, when combined, give you the resistance value in ohms. The color codes for the bands are:

1. First band (1st digit):
   • Brown: 1
   • Blue: 6
   • No color: 20
2. Second band (2nd digit):
   • Black: 0
   • Green: 5
3. Multiplier (3rd band):
   • Red: (10^2 = 100)
   • Orange: (10^3 = 1000)
   • Gold: (10^{-1} = 0.1)
4. Tolerance (4th band):
   • No color (or silver): ±10%
   • Silver: ±10%

Using this information, we can decode the resistor values:

i. Brown Black Red (No color):

• Brown: 1
• Black: 0
• Red: (10^2 = 100)
• No color (20% tolerance)

This represents a resistor value of (10 \times 10^0 \times 100) ohms, which is (1000) ohms or (1) kilo-ohm with a (20%) tolerance.

ii. Blue Green Orange Silver:

• Blue: 6
• Green: 5
• Orange: (10^3 = 1000)
• Silver (10% tolerance)

This represents a resistor value of (65 \times 10^3) ohms, which is (65) kilo-ohms or (65,000) ohms with a (10%) tolerance.

iii. While Blue Yellow Gold:

• Blue: 6
• Yellow: 4
• Gold ((10^{-1}) tolerance)

This represents a resistor value of (64 \times 10^{-1}) ohms, which is (6.4) ohms with a (5%) tolerance.

Note: The value “No color” for the first resistor should be interpreted as “No significant digit,” which effectively means “ignore this band for the resistance value calculation.”

7) Write the color code of following resistors for four band resistor.

• 4.7kohm
• 27 ohm
• 1 Mega ohm

To determine the color code for a four-band resistor, you need to follow the standard resistor color code, which consists of four bands representing the resistance value, tolerance, and sometimes the temperature coefficient. Here’s how you can decode the color code for each resistor:

i. 4.7 kilo-ohm (4.7 kΩ):

• First band (1st digit): Yellow (4)
• Second band (2nd digit): Violet (7)
• Multiplier (3rd band): Red ((10^2 = 1000))
• Tolerance (4th band): Gold (5%)

So, the color code for a 4.7 kilo-ohm resistor would be: Yellow Violet Red Gold.

ii. 27 ohms (27 Ω):

• First band (1st digit): Red (2)
• Second band (2nd digit): Violet (7)
• Multiplier (3rd band): Black (10(^0 = 1))
• Tolerance (4th band): Gold (5%)

So, the color code for a 27 ohm resistor would be: Red Violet Black Gold.

iii. 1 Mega-ohm (1 MΩ):

• First band (1st digit): Brown (1)
• Second band (2nd digit): Black (0)
• Multiplier (3rd band): Green ((10^6 = 1000000))
• Tolerance (4th band): Brown (1%)

So, the color code for a 1 Mega-ohm resistor would be: Brown Black Green Brown.

These color codes are used to visually represent the resistance value and tolerance of the resistor for easy identification in electronic circuits.

8) Write the procedure to test for following electronic components.

• Diode
• Transistor
• LED

To test electronic components like diodes, transistors, and LEDs, you can use a multimeter. Here’s a general procedure for testing each component:

1. Diode:
   • Forward Bias Test: Set your multimeter to the diode test mode (usually indicated by a diode symbol). Place the positive (red) probe on the anode (longer lead) and the negative (black) probe on the cathode (shorter lead). The multimeter should display a voltage drop (typically around 0.6 to 0.7 volts) if the diode is good.
   • Reverse Bias Test: Reverse the probes. The multimeter should display an “open circuit” or a very high resistance reading. If the diode shows a low resistance in both directions, it’s likely damaged.
2. Transistor:
   • NPN Transistor: Set your multimeter to the diode test mode. Place the positive (red) probe on the base and the negative (black) probe on the emitter. Note the reading. Then, switch the probes so that the positive probe is on the base and the negative probe is on the collector. You should get two voltage drops (around 0.6 to 0.7 volts) if the transistor is NPN and functional.
   • PNP Transistor: Follow the same procedure as for NPN, but the polarity of the readings will be reversed.
3. LED (Light Emitting Diode):
   • Forward Bias Test: Set your multimeter to the diode test mode. Place the positive (red) probe on the anode (longer lead) and the negative (black) probe on the cathode (shorter lead). The LED should light up, and the multimeter should display a voltage drop (around 1.8 to 3.3 volts, depending on the LED color).
   • Reverse Bias Test: Reverse the probes. The LED should not light up, and the multimeter should display an “open circuit” or a very high resistance reading.

Always refer to the component’s datasheet for specific voltage drop values and polarity.

12) Define the followings:

A. Analog Signal B. Digital Signal C. bit rate & baud rate

A. Analog Signal:

• An analog signal is a continuous, time-varying signal that represents physical quantities such as voltage, current, or sound waves. It can take on an infinite number of values within a certain range. Analog signals are used to represent real-world phenomena that are continuous in nature, such as audio and video signals.

B. Digital Signal:

• A digital signal is a discrete, non-continuous signal that represents data as a sequence of discrete values. These values are typically represented using binary digits (bits), where each bit can be either a 0 or a 1. Digital signals are used in digital electronics and computing systems, where data is processed and transmitted in a digital format.

C. Bit Rate & Baud Rate:

• Bit Rate: Bit rate, also known as data rate, is the number of bits transmitted or processed per unit of time. It is usually expressed in bits per second (bps) or kilobits per second (kbps). Bit rate is a measure of the amount of data that can be transmitted in a given period and is used to describe the speed of digital communication channels.
• Baud Rate: Baud rate, also known as symbol rate, is the number of signal changes (or symbol changes) per second in a communication channel. It is used to describe the rate at which symbols (such as bits, characters, or data elements) are transmitted in a digital communication system. Baud rate is typically expressed in symbols per second (baud) or baud per second (baud/s).

13) Explain the process of Analog-to Digital conversion with a neat sketch of block diagram.

Analog-to-Digital Conversion (ADC) is the process of converting continuous analog signals into discrete digital signals. This conversion is necessary for digital processing and storage of analog signals in applications such as audio recording, digital communications, and control systems. Here’s a simplified explanation along with a block diagram:

1. Sampling: The first step in ADC is sampling, where the continuous analog signal is sampled at regular intervals to capture its amplitude. The sampling rate, measured in samples per second (S/s) or Hertz (Hz), determines the accuracy of the digital representation.
2. Quantization: Once the signal is sampled, the next step is quantization, where each sample’s amplitude is approximated to the nearest digital value. This process involves dividing the analog signal’s amplitude range into discrete levels based on the desired resolution (number of bits).
3. Encoding: The quantized samples are then encoded into binary digits (bits) using an encoder. Each sample is represented by a binary code that corresponds to its quantized amplitude.
4. Output: The digital representation of the analog signal is then available for further processing or storage in digital systems.

Here’s a block diagram illustrating the process:

+------------+    +-----------+    +--------------+    +-------+
| Analog     |    | Sampling  |    | Quantization |    | Output|
| Signal     +--->| Circuit   +--->| Circuit      +--->|       |
|            |    |           |    |              |    |       |
+------------+    +-----------+    +--------------+    +-------+
                                   |  Encoding    |
                                   |  Circuit     |
                                   +--------------+

In this diagram:

• The Analog Signal is the continuous input signal that needs to be converted.
• The Sampling Circuit samples the analog signal at regular intervals.
• The Quantization Circuit approximates the sampled values to discrete levels.
• The Encoding Circuit encodes the quantized values into binary code.
• The Output is the digital representation of the analog signal.

14) A television signal with a bandwidth of 4.2 MHZ is transmitted using ADC process. The number of quantization level is 512. Calculate,

• Code word length
• Minimum Sampling frequency

Analog-to-Digital Conversion (ADC) Process:

Analog-to-digital conversion is the process of converting continuous analog signals into discrete digital signals. This process involves two main steps: sampling and quantization.

1. Sampling: The continuous analog signal is sampled at regular intervals to obtain discrete samples. The sampling frequency, ( f_s ), determines how often the signal is sampled. The sampling process is represented by the “Sample” block in the diagram.
2. Quantization: Each sample is then quantized into a discrete digital value. The analog signal amplitude is divided into a finite number of levels, and each sample is assigned to the closest quantization level. The number of quantization levels determines the resolution of the ADC. The quantization process is represented by the “Quantization” block in the diagram.
3. Encoding: Finally, the quantized samples are encoded into digital binary code words. The code word length is determined by the number of quantization levels. The digital output represents the discrete digital representation of the original analog signal.

Here is a block diagram illustrating the process:

          +-------------+   +-----------------+   +---------+
Analog -> |   Sampling  | ->|   Quantization   | ->| Encoding| -> Digital
 Signal   +-------------+   +-----------------+   +---------+

In this diagram:

• Analog Signal: Represents the continuous input signal to be converted.
• Sampling: Samples the analog signal at a specified rate to produce discrete samples.
• Quantization: Converts the analog samples into discrete digital values.
• Encoding: Converts the quantized values into binary code words.

Now, to calculate the code word length and minimum sampling frequency for the given television signal:

Given:

• Bandwidth = 4.2 MHz
• Number of quantization levels = 512

Code Word Length: The number of quantization levels, ( L ), is given by ( L = 2^n ), where ( n ) is the number of bits used for encoding. In this case, ( L = 512 ), so ( n = \log_2(512) = 9 ) bits.

Therefore, the code word length is 9 bits.

Minimum Sampling Frequency: According to the Nyquist-Shannon sampling theorem, the minimum sampling frequency, ( f_s ), should be at least twice the bandwidth of the signal to avoid aliasing. Therefore, ( f_s \geq 2 \times 4.2 ) MHz.

Hence, the minimum sampling frequency is ( f_s \geq 8.4 ) MHz.