MODULE -01 FUNDAMENTALS OF ELECTRICITY
Basic laws -Method of Solving a Circuit by Kirchhoff’s Laws - Wiring Layout for a Residential Building- Basic Principles of Earthling-Un Interrupted Power Supply and its Types-Evolution of electric grid –Need for smart grid- National and International initiatives in smart grid- Comparison between conventional grid and smart grid.
PART A
1 Define Ohm's Law.
Ohm's Law states that at constant temperature the current (I) passing through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R). The formula is V=IR
Limitations
Ohm’s Law does not apply to all non-metallic conductors
It also does not apply to non-linear devices such as Zener diode, voltage regulator (VR) tubes and the like.
Ohm’s law is true for metal conductors at constant temperature.
2 Define Kirchhoff's Voltage Law (KVL).
Kirchhoff's Voltage Law states that the sum of all electrical potential differences around any closed network is zero. In other words, the total voltage around a closed loop is equal to the sum of voltage drops within the same loop.
3 State Kirchhoff's Current Law (KCL).
Kirchhoff's Current Law (KCL) states that the total current entering a junction or node is equal to the total current leaving the node.
4 What is the purpose of a circuit breaker in a residential wiring layout?
The purpose of a circuit breaker is to protect an electrical circuit from damage caused by overcurrent or short circuit. It automatically interrupts the current flow when a fault is detected.
5 Why is it important to have a ground wire in a residential electrical system?
The ground wire provides a safe path for electrical current to travel in the event of a short circuit, reducing the risk of electric shock and fire.
6 What is the standard voltage supply for residential buildings in most countries?
The standard voltage supply for residential buildings in most countries is either 120/240 volts or 230 volts, depending on the country's electrical standards.
7 Why are different colors used for electrical wiring in residential buildings?
Different colors are used for electrical wiring to indicate the function of the wires (e.g., live, neutral, and ground) and to ensure safety by preventing incorrect connections.
8 What is the primary purpose of earthing (grounding) in an electrical system?
The primary purpose of earthing is to provide a safe path for fault currents to flow to the ground, preventing electric shock hazards and protecting equipment from damage.
9 What is a grounding conductor, and what material is it commonly made from?
A grounding conductor is a wire that connects the electrical system to the earth. It is commonly made from copper or aluminum due to their excellent conductivity and resistance to corrosion.
10 What is an Uninterrupted Power Supply (UPS)?
An Uninterrupted Power Supply (UPS) is a device that provides emergency power to a load when the input power source, typically the mains, fails.
11 What are the three main types of UPS systems?
The three main types of UPS systems are Offline/Standby UPS, Line-Interactive UPS, and Online/Double-Conversion UPS.
12 Explain the working principle of an Offline/Standby UPS.
An Offline/Standby UPS provides power directly from the mains during normal operation and switches to battery power in the event of a power failure, typically with a few milliseconds of delay.
13 How does a Line-Interactive UPS differ from an Offline UPS?
A Line-Interactive UPS uses a built-in automatic voltage regulator (AVR) to correct minor power fluctuations without switching to battery power, offering better protection than an Offline UPS.
14 What is the main advantage of an Online/Double-Conversion UPS?
The main advantage of an Online/Double-Conversion UPS is that it provides the highest level of power protection by continuously converting incoming AC power to DC and then back to AC, ensuring a consistent and clean power supply.
15 What role does a battery play in a UPS system?
The battery in a UPS system stores energy and provides power to the load during a power outage or when the main power supply is unstable.
16 Define the term 'UPS runtime’.
UPS runtime refers to the duration for which a UPS can provide power to the connected load during a power outage, determined by the capacity of its battery.
17 What is the significance of transfer time in a UPS?
Transfer time is the time it takes for a UPS to switch from mains power to battery power during an outage. Shorter transfer times ensure minimal disruption to connected equipment.
18 How can the load capacity of a UPS be calculated?
The load capacity of a UPS can be calculated by summing up the total power requirements (in watts or VA) of all connected devices and ensuring it does not exceed the UPS's rated capacity.
19 Explain the difference between alternating current (AC) and direct current (DC).
Direct current (DC) flows in one direction, while alternating current (AC) changes direction periodically. AC is typically used for power distribution because it is more efficient for long-distance transmission.
20 What is a smart grid, and how does it differ from a traditional electric grid?
A smart grid is an advanced electrical grid that incorporates digital technology to monitor, control, and optimize the production and distribution of electricity. It differs from a traditional grid by using real-time data and communication to enhance efficiency, reliability, and sustainability.
21 How does a smart grid improve energy efficiency for consumers?
A smart grid improves energy efficiency by providing consumers with real-time data on their energy usage, allowing them to adjust their consumption patterns, reduce waste, and lower their electricity bills.
22 Explain the role of smart meters in a smart grid.
Smart meters are devices that provide real-time monitoring and reporting of electricity usage to both consumers and utilities. They enable dynamic pricing, better demand response, and more efficient energy management.
23 How does the implementation of smart grids support the modernization of aging electrical infrastructure?
The implementation of smart grids supports modernization by upgrading outdated components with advanced technology, improving system performance, and extending the lifespan of the existing infrastructure, thereby meeting current and future energy demands more effectively.
24 List the different types of earthing
Plate earthing
Pipe earthing
Strip or wire earthing
Rod earthing
Grid earthing
25 Compare Smart grid and conventional grid
MODULE 2 DIGITAL ELECTRONICS
Number system –Boolean algebra-Logic gates- Combinational Logic Design- Karnaugh Map representation of logical functions- Combinational Logic: Half adder, full adder, subtractor circuit – Sequential: Flip flops(JK, RS, D and T) – Counters: Synchronous and Asynchronous counters.
PART A
1 Convert the binary number 1101 to its decimal equivalent. 13.
2 What is the hexadecimal representation of the binary number 101011? 2B.
3 How do you represent the decimal number 25 in binary? 11001.
4 State De Morgan’s Theorem.
De Morgan’s Theorem states that (A∙B)’ = A’ + B’ and (A + B)’ = A’ ∙ B’.
5 Which logic gate is known as a universal gate and why?
The NAND & NOR gate is known as a universal gate because it can be used to implement any Boolean function.
6 What is the primary purpose of a Karnaugh Map? How many cells are there in a 3-variable Karnaugh Map?
To simplify Boolean expressions.
8 cells.
7 Define combinational logic.
Combinational logic is a type of digital logic where the output is a pure function of the present input only.
8 Define sequential logic.
Sequential logic is a type of logic circuit whose output depends on both the current input and the history of inputs
9 What is the main difference between combinational and sequential logic?
Combinational logic outputs depend only on the current inputs, whereas sequential logic outputs depend on both current and past inputs.
10 Explain how a half adder differs from a full adder in terms of inputs and outputs.
A half adder adds two single-bit inputs without considering any carry input, while a full adder adds three inputs (two bits and a carry-in) to produce a sum and carry-out.
11 State the definition of a flip-flop in digital electronics.
A flip-flop is a sequential logic circuit that can store one bit of binary data.
12 Name types of flip-flops commonly used in digital circuits.
Types of flip-flops are RS (Reset-Set), JK (Jack Kilby), D (Data), and T (Toggle).
13 Explain how a JK flip-flop differs from an RS flip-flop.
A JK flip-flop has two inputs (J and K) that can toggle its state, whereas an RS flip-flop has Set (S) and Reset (R) inputs to set or reset its state.
JK flip-flops offer versatility and reduced race conditions compared to RS flip-flops but require more complex logic. RS flip-flops are simpler but prone to race conditions.
14 Describe a T flip-flop.
A T flip-flop toggles its output on each clock cycle if the T input is high.
15 What is the primary application of a D flip-flop?
A D flip-flop is used to store a single bit of data.
16 Define an asynchronous counter.
An asynchronous counter, also known as a ripple counter, is a type of counter where the flip-flops are not clocked simultaneously. The output of one flip-flop serves as the clock input for the next flip-flop in the sequence.
17 What is a synchronous counter?
A synchronous counter is a type of counter where all the flip-flops are clocked simultaneously by a common clock signal, ensuring that all the flip-flops change state at the same time
18 Explain the main difference between synchronous and asynchronous counters.
The main difference is that in synchronous counters, all flip-flops are triggered by the same clock signal simultaneously, whereas in asynchronous counters, flip-flops are triggered one after another, causing a ripple effect.
19 Why are asynchronous counters called "ripple counters"?
Asynchronous counters are called "ripple counters" because the change in state ripples through the flip-flops sequentially, causing a delay in the final output as each flip-flop waits for the previous one to toggle.
20 How would you connect flip-flops to create a 4-bit asynchronous counter?
To create a 4-bit asynchronous counter, connect the clock input to the first flip-flop, then connect the output of each flip-flop to the clock input of the next flip-flop in sequence.
21 Evaluate the suitability of using asynchronous counters in high-speed applications. Asynchronous counters are generally unsuitable for high-speed applications due to their cumulative propagation delays, which can cause timing issues and limit the overall speed of the counter.
22 Assess the advantages of synchronous counters over asynchronous counters in digital circuits.
Synchronous counters are advantageous because they eliminate cumulative delays, provide faster and more reliable operation, and are easier to design and troubleshoot in complex digital circuits.
MODULE 03 INSTRUMENTATION AND COMMUNICATION
Functional elements of an instrument – Errors in measurement - Operation of various Digital Meters – Voltmeter, Ammeter and Single phase energy meter-Optical fibres, Satellite communication and Mobile communication- Advanced metering infrastructure (AMI) need in the smart grid – Basic Principle of modulation and techniques.
1 What are the three primary functional elements of an instrument?
Sensing, Signal Processing, and Display/Recording.
2 Define the term "sensor" in the context of instrumentation.
A sensor is a device that detects changes in physical parameters and converts them into signals that can be measured.
3 What is the role of a transducer in an instrument?
A transducer converts one form of energy into another, typically converting physical quantities into electrical signals.
4 Describe the purpose of a signal conditioner.
A signal conditioner modifies the signal from a sensor to a form that is suitable for further processing or display.
5 Compare the advantages of digital instruments over analog instruments.
Digital instruments offer higher accuracy, better resolution, ease of data storage and processing, and less susceptibility to noise.
6 Draw the block diagram of functional elements of an instrument
7 Define systematic error.
Systematic error is a consistent, repeatable error associated with faulty equipment or a flawed experimental design, which affects all measurements in the same way.
8 How can systematic errors be minimized?
Systematic errors can be minimized by regularly calibrating instruments, using more precise equipment, and employing standardized measurement techniques.
9 What is a random error?
Random error is an error in measurement caused by unpredictable fluctuations in the measurement process, which leads to variation in results.
10 Assess the impact of environmental conditions on measurement accuracy.
Environmental conditions such as temperature, humidity, and pressure can significantly impact measurement accuracy by causing changes in the measuring instrument or the item being measured, leading to errors.
11 Describe how a digital voltmeter displays the measured voltage.
It converts the analog voltage into a digital value using an analog-to-digital converter (ADC) and displays the result on a digital screen.
12 Define what a single-phase energy meter is.
A single-phase energy meter is a device used to measure and record electrical energy consumption in single-phase AC circuits. The basic unit is kilowatt-hour (kWh).
13 Explain how the rotating disc in an electromechanical energy meter functions.
The rotating disc rotates proportionally to the energy consumption due to the interaction of magnetic fields.
14 Define optical fiber.
Optical fiber is a thin, transparent fiber made of glass or plastic used to transmit light signals over long distances.
15 What is the main advantage of optical fibers in communication?
High bandwidth and low signal loss.
16 Define geostationary satellite.
A satellite that orbits the Earth at the same speed and direction as the Earth's rotation, appearing stationary from the ground.
17 Explain how total internal reflection is used in optical fibers.
Total internal reflection allows light signals to propagate through the core of the fiber by continuously reflecting off the cladding.
18 How do satellites communicate with ground stations in satellite communication?
Satellites communicate by receiving signals from ground stations, amplifying them, and retransmitting them back to Earth.
19 Define Advanced Metering Infrastructure (AMI).
AMI is an integrated system of smart meters, communication networks, and data management systems for collecting and analyzing energy usage data.
20 What is the primary purpose of AMI in the smart grid?
The primary purpose is to enable two-way communication between utility companies and consumers for real-time monitoring and management of energy usage.
21 Compare AMI with traditional metering systems in terms of data collection and management.
AMI enables automated data collection and real-time monitoring, unlike traditional systems that require manual readings.
22 Define modulation.
Modulation is the process of varying one or more properties of a high-frequency periodic waveform (carrier signal) in accordance with the information signal.
23 Explain the basic principle of Amplitude Modulation (AM).
In AM, the amplitude of the carrier signal is varied in proportion to the amplitude of the modulating signal.
24 Describe Frequency Modulation (FM) in brief.
FM varies the frequency of the carrier signal according to the amplitude of the modulating signal.
25 How is Pulse Amplitude Modulation (PAM) different from AM?
PAM directly varies the amplitude of a series of pulses according to the amplitude of the modulating signal, while AM varies the amplitude of a continuous wave.
26 Analyze the advantages of Frequency Modulation (FM) over Amplitude Modulation (AM).
FM is less susceptible to noise and provides better sound quality compared to AM.
27 Compare Pulse Width Modulation (PWM) with Pulse Position Modulation (PPM).
PWM varies the width of pulses, while PPM varies the position of pulses in response to the modulating signal.
28 Mention how voltmeter and ammeter are connected in an electric circuits
A voltmeter is always connected in parallel with the component or points across which the voltage is to be measured.
An ammeter is always connected in series with the circuit element through which the current is to be measured.
No comments:
Post a Comment