This document discusses alternating current (AC). It describes the characteristics of AC including period, frequency, peak value and root-mean-square value. It also discusses how AC power is transmitted through transformers and rectified to direct current (DC) for applications. Key points covered include the rms and peak values of AC, mean power in a resistive load, representation of AC by equations, transformer principles and ratios, transmission of power at high voltages to reduce losses, and half-wave and full-wave rectification using diodes.
Diploma sem 2 applied science physics-unit 1-chap 1 measurementsRai University
This document provides an overview of measurements and units in physics. It defines fundamental concepts like physical quantities, units, and dimensions. The three fundamental SI units are outlined as the meter, kilogram, and second. Derived units are defined based on combinations of the fundamental units, such as meters/second for velocity. Several systems of units are described including the MKS, CGS, and FPS systems, with SI (metric) noted as the international standard. Conversions between units are demonstrated through examples. Dimensional analysis is introduced as a tool for checking equations and deducing relationships between physical phenomena.
This is a ppt of a college project of the topic kvl and kcl ..do read this..i have such interest in science projects and do maake aa lot of money by doing freelancing in embedded system so make sure to check this ppt for more updtes
The document describes a two port network and provides information about various parameter representations of two port networks, including:
- Z parameters define the input and transfer impedances between the two ports.
- Y parameters define the input and transfer admittances between the two ports.
- Transmission parameters (A,B,C,D) define relationships between voltages and currents at the two ports.
- Hybrid parameters also define relationships between voltages and currents at the two ports.
Examples are provided to demonstrate calculating the parameter representations for given two port networks. Additionally, the document discusses how modifying a two port network impacts its parameter representations.
This document outlines the syllabus and content for a basic electronics course. It discusses that the course grade will be based on midterm, final, and sessional marks. Sessional marks depend on behavior, participation, assignments, presentations, attendance, and quizzes. Contact information for the instructor is provided. Recommended reference materials are listed. An introduction to electronics and its role in daily life is given. The history of electronics from vacuum tubes to integrated circuits is summarized. Fundamental electronics components like resistors, capacitors, diodes, and transistors are defined. Band theory, intrinsic and extrinsic semiconductors, and PN junctions are explained conceptually. Students will have a homework assignment on electricity and magnetism
The document discusses Boolean algebra laws, which are used to simplify Boolean expressions. It outlines several important laws including:
1) Identity laws - A variable combined with 1 or 0 is equal to itself
2) Annulment laws - A variable combined with 0 under AND or 1 under OR is always equal to 0 or 1, respectively
3) Idempotent laws - A variable combined with itself under AND or OR is equal to itself
4) Complement laws - A variable combined with its complement under AND or OR is always equal to 0 or 1, respectively
5) De Morgan's laws - Allow transforming expressions containing negation, AND, and OR operations.
The document is notes on information theory and coding created by Akshansh Chaudhary based on lectures from Dr. Anand Kumar. It includes disclaimers about the accuracy of the information and reserves the right to modify or limit access to the content. The notes were created in 2014 and cover topics related to information theory and coding.
This document discusses phase and phase difference in waves. It provides definitions of standing waves, which have nodes where the wave disturbance is minimal, and traveling waves, which do not have nodes. The displacement equation for traveling waves includes a term for velocity (v) to account for waves moving in the positive or negative x direction. Phase describes the wave's position and time, while phase difference is the difference in phases between two waves at the same time. A worked example shows waves A and B with a phase difference of 3π/2, and calculates their distance apart as 3λ/4, where λ is the wavelength.
Diploma sem 2 applied science physics-unit 1-chap 1 measurementsRai University
This document provides an overview of measurements and units in physics. It defines fundamental concepts like physical quantities, units, and dimensions. The three fundamental SI units are outlined as the meter, kilogram, and second. Derived units are defined based on combinations of the fundamental units, such as meters/second for velocity. Several systems of units are described including the MKS, CGS, and FPS systems, with SI (metric) noted as the international standard. Conversions between units are demonstrated through examples. Dimensional analysis is introduced as a tool for checking equations and deducing relationships between physical phenomena.
This is a ppt of a college project of the topic kvl and kcl ..do read this..i have such interest in science projects and do maake aa lot of money by doing freelancing in embedded system so make sure to check this ppt for more updtes
The document describes a two port network and provides information about various parameter representations of two port networks, including:
- Z parameters define the input and transfer impedances between the two ports.
- Y parameters define the input and transfer admittances between the two ports.
- Transmission parameters (A,B,C,D) define relationships between voltages and currents at the two ports.
- Hybrid parameters also define relationships between voltages and currents at the two ports.
Examples are provided to demonstrate calculating the parameter representations for given two port networks. Additionally, the document discusses how modifying a two port network impacts its parameter representations.
This document outlines the syllabus and content for a basic electronics course. It discusses that the course grade will be based on midterm, final, and sessional marks. Sessional marks depend on behavior, participation, assignments, presentations, attendance, and quizzes. Contact information for the instructor is provided. Recommended reference materials are listed. An introduction to electronics and its role in daily life is given. The history of electronics from vacuum tubes to integrated circuits is summarized. Fundamental electronics components like resistors, capacitors, diodes, and transistors are defined. Band theory, intrinsic and extrinsic semiconductors, and PN junctions are explained conceptually. Students will have a homework assignment on electricity and magnetism
The document discusses Boolean algebra laws, which are used to simplify Boolean expressions. It outlines several important laws including:
1) Identity laws - A variable combined with 1 or 0 is equal to itself
2) Annulment laws - A variable combined with 0 under AND or 1 under OR is always equal to 0 or 1, respectively
3) Idempotent laws - A variable combined with itself under AND or OR is equal to itself
4) Complement laws - A variable combined with its complement under AND or OR is always equal to 0 or 1, respectively
5) De Morgan's laws - Allow transforming expressions containing negation, AND, and OR operations.
The document is notes on information theory and coding created by Akshansh Chaudhary based on lectures from Dr. Anand Kumar. It includes disclaimers about the accuracy of the information and reserves the right to modify or limit access to the content. The notes were created in 2014 and cover topics related to information theory and coding.
This document discusses phase and phase difference in waves. It provides definitions of standing waves, which have nodes where the wave disturbance is minimal, and traveling waves, which do not have nodes. The displacement equation for traveling waves includes a term for velocity (v) to account for waves moving in the positive or negative x direction. Phase describes the wave's position and time, while phase difference is the difference in phases between two waves at the same time. A worked example shows waves A and B with a phase difference of 3π/2, and calculates their distance apart as 3λ/4, where λ is the wavelength.
This document contains a lab manual for experiments in electronic circuit design using mechatronics engineering. It includes 10 listed experiments involving various components like SCRs, DIACs, TRIACs, op-amps, and filters. Experiment 1 details obtaining the V-I characteristics of an SCR to find the break over voltage and holding current. Experiment 4 involves designing inverting and non-inverting amplifiers using op-amps. Experiment 8 analyzes the effect of varying frequency on the output voltage of low-pass and high-pass filters.
This document provides an overview of amplitude (linear) modulation techniques. It defines key concepts like modulation, baseband communication, and carrier communication. It then describes various amplitude modulation schemes including AM, DSB-SC, QAM, SSB, and VSB. Implementation and demodulation of these techniques is discussed. The document also covers frequency mixing, superheterodyne receivers, frequency division multiplexing, and carrier acquisition using phase-locked loops. Suggested problems are provided at the end.
Clamping Circuit and Clipping Circuit, Principle of Operation of Clamping Circuit, Biased positive clamping circuit, Biased negative clamping circuit, Classification of Clipping Circuit, Clipping Circuit, Zener Diode as a Peak Clipper, Application of Clipper.
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The document discusses alternating current (AC) and direct current (DC). It defines AC as current that reverses direction periodically and describes its generation from sources like power plants. Key aspects of AC covered include its sinusoidal waveform, frequency, peak and RMS values. Phasors are introduced as a way to represent AC quantities in terms of magnitude and phase. Circuit laws for resistive AC circuits are also mentioned.
This document discusses discrete-time signals and sequences. It defines discrete-time signals as sequences of numbers represented as x[n], where n is an integer. In practice, sequences arise from periodically sampling an analog signal. Linear time-invariant (LTI) systems are described by the convolution sum, where the impulse response h[n] completely characterizes the system. FIR systems have impulse responses of finite duration, while IIR systems can have impulse responses that extend to infinity.
Kirchhoff's Voltage Law (KVL) states that the sum of all voltages around a closed loop in an electrical circuit is equal to zero. KVL can be expressed mathematically as an equation where the applied voltage equals the sum of all voltage drops around the loop. An example problem was provided to demonstrate applying KVL with an equation to solve for unknown voltages in a circuit.
Registers are groups of flip-flops that store binary data. An n-bit register contains n flip-flops and can store 2^n different states. Registers are used to store and provide digital data to logic circuits. There are different types of registers including shift registers. Shift registers can transfer data in serial-in serial-out, serial-in parallel-out, parallel-in serial-out, and parallel-in parallel-out modes. Counters are registers that increment their stored value on each clock pulse and are used to count events.
The document discusses several topics in electrostatics including electric potential, potential difference, equipotential surfaces, Gauss's law, and applications of Gauss's law. Gauss's law states that the electric flux through any closed surface is equal to the enclosed charge divided by the permittivity of free space. This relationship can be used to derive Coulomb's law and calculate electric fields due to various charge distributions like line charges, plane sheets of charge, and spherical shells.
Double Side band Suppressed carrier (DSB-SC) Modulation and Demodulation.SAiFul IslAm
This document describes an experiment on double sideband suppressed carrier (DSB-SC) modulation and demodulation performed by electrical engineering students at the University of Asia Pacific. The objectives were to observe DSB-SC modulation using an MC1496 modulator and examine synchronous demodulation of DSB-SC signals. The experiment involved generating a message signal, carrier signal, and DSB-SC modulated signal. A balanced modulator was used to produce the DSB-SC signal. Synchronous demodulation using a balanced multiplier, low-pass filter, and same carrier signal as the modulator recovered the original message signal from the DSB-SC signal. The students observed input and output waveforms and discussed the circuit connections and results
Ampere's law relates the magnetic field around a closed loop to the electric current passing through the loop. It states that the line integral of the magnetic field around the loop equals the net current passing through the loop times the permeability of free space. The document provides examples of using Ampere's law to calculate magnetic fields for various current carrying wire configurations, including inside and outside a long straight wire, inside a solenoid, and inside and outside a toroidal coil.
This presentation covers scalar quantity, vector quantity, addition of vectors & multiplication of vector. I hope this PPT will be helpful for Instructors as well as students.
This document summarizes an experiment on diode clipping and clamping circuits. It includes the objectives, equipment used, circuit diagrams of clipping and clamping circuits tested, and results from those circuits. Key findings are: 1) clipping circuits cut off portions of the input signal above or below certain voltage thresholds, while clamping circuits shift the entire signal up or down by a fixed amount. 2) In a clipping circuit, diodes allow the output to follow the input until a threshold is reached, then clamp the output at that level. 3) A clamping circuit uses a capacitor, diode, and resistor to shift the entire signal down by twice the peak input voltage.
1) Alternating current (AC) refers to sinusoidal voltage and current waveforms. AC can be generated from sources like AC generators, wind turbines, hydroelectric power plants, and solar panels.
2) Key characteristics of AC waveforms include instantaneous value, peak amplitude, peak value, peak-to-peak value, period, frequency, phase, and whether they are periodic.
3) Sinusoidal waves can be expressed as v = Vm sin(ωt+θ), where Vm is the peak amplitude, ω is the angular frequency, t is time, and θ is the phase. The phase relationship between two sinusoidal waves indicates whether one leads or lags the other.
The document discusses vector calculus concepts including:
- Vector product has magnitude equal to the area of the parallelogram formed by the vectors and is perpendicular to both vectors.
- Scalar triple product equals the volume of the parallelepiped formed by the three vectors and represents the scalar quantity obtained by multiplying the vectors in a specific order.
- Vector triple product follows the "bac-cab" rule and results in another vector quantity.
This document discusses parallel circuits. It defines parallel circuits as having multiple paths for current to flow and that the voltage is the same across each component. The total resistance of a parallel circuit is smaller than its branches because the overall conductance is the sum of the individual conductances. The current divider rule is used to calculate the current through each resistor in a parallel circuit.
Gauss's law relates the electric flux through a closed surface to the electric charge enclosed by the surface. It can be used to calculate the electric field due to various charge distributions like:
- A point charge, where the electric field is spherically symmetric and directed radially outward.
- An infinite line charge, where the electric field is directed radially outward and its magnitude depends only on the distance from the wire.
- An infinite plane sheet, where the electric field is uniform and perpendicular to the sheet.
- Two parallel charged sheets, where the electric field is zero outside and uniform inside, directed from the positive to negative sheet.
- A charged spherical shell, where the electric field
B.Tech sem I Engineering Physics U-III Chapter 1-THE SPECIAL THEORY OF RELATI...Abhi Hirpara
The document discusses Einstein's theory of special relativity. It provides background on Einstein's two postulates: 1) the laws of physics are the same in all inertial frames of reference, and 2) the speed of light in a vacuum is the same for all observers regardless of their motion. It describes how these postulates led Einstein to develop the Lorentz transformations, which show that time and space are relative between different frames of reference moving at a constant velocity with respect to each other.
This document discusses signals and their classification. It defines signals, analog and digital signals, periodic and aperiodic signals. It also discusses representing signals in Matlab and Simulink. Key signal types covered include exponential, sinusoidal, unit impulse and step functions. Matlab is presented as a tool for programming and analyzing discrete signals while Simulink can be used to model and simulate continuous systems.
This document provides an overview of basic electronics concepts including lattices, semiconductors, diodes, and transistors. It begins by defining lattices and their applications in mathematics. It then discusses superconductors, insulators, intrinsic and extrinsic semiconductors, and the band theory of conduction. Diodes and rectifiers are introduced, including half-wave and full-wave rectification circuits. The document concludes by explaining transistors, including bipolar junction transistors with npn and pnp configurations and their characteristics curves. Transistors are shown to have applications as amplifiers and switches in devices like LED spotlights and single transistor radios.
This document summarizes key concepts about transformers:
1) Transformers transfer electrical energy from one voltage level to another through a magnetic field without changing frequency. They have a primary and secondary winding wound around an iron core.
2) An AC voltage applied to the primary induces a voltage in the secondary according to Faraday's Law of induction. The ratio of voltages is determined by the ratio of turns in the windings.
3) Real transformers have losses that are modeled in an equivalent circuit including resistances of the windings and core and a magnetizing reactance. Impedances can be transferred between windings using the turns ratio.
This document summarizes key concepts about transformers:
1) Transformers transfer electrical energy from one voltage level to another through magnetic coupling between primary and secondary coils. They do not directly convert electrical to mechanical energy.
2) An ideal transformer transfers power without losses, but real transformers have resistive losses in their coils and core that reduce efficiency.
3) The voltage and current ratios between primary and secondary coils are determined by their relative turn ratios; this relationship allows impedances to be transferred between sides.
This document contains a lab manual for experiments in electronic circuit design using mechatronics engineering. It includes 10 listed experiments involving various components like SCRs, DIACs, TRIACs, op-amps, and filters. Experiment 1 details obtaining the V-I characteristics of an SCR to find the break over voltage and holding current. Experiment 4 involves designing inverting and non-inverting amplifiers using op-amps. Experiment 8 analyzes the effect of varying frequency on the output voltage of low-pass and high-pass filters.
This document provides an overview of amplitude (linear) modulation techniques. It defines key concepts like modulation, baseband communication, and carrier communication. It then describes various amplitude modulation schemes including AM, DSB-SC, QAM, SSB, and VSB. Implementation and demodulation of these techniques is discussed. The document also covers frequency mixing, superheterodyne receivers, frequency division multiplexing, and carrier acquisition using phase-locked loops. Suggested problems are provided at the end.
Clamping Circuit and Clipping Circuit, Principle of Operation of Clamping Circuit, Biased positive clamping circuit, Biased negative clamping circuit, Classification of Clipping Circuit, Clipping Circuit, Zener Diode as a Peak Clipper, Application of Clipper.
,
The document discusses alternating current (AC) and direct current (DC). It defines AC as current that reverses direction periodically and describes its generation from sources like power plants. Key aspects of AC covered include its sinusoidal waveform, frequency, peak and RMS values. Phasors are introduced as a way to represent AC quantities in terms of magnitude and phase. Circuit laws for resistive AC circuits are also mentioned.
This document discusses discrete-time signals and sequences. It defines discrete-time signals as sequences of numbers represented as x[n], where n is an integer. In practice, sequences arise from periodically sampling an analog signal. Linear time-invariant (LTI) systems are described by the convolution sum, where the impulse response h[n] completely characterizes the system. FIR systems have impulse responses of finite duration, while IIR systems can have impulse responses that extend to infinity.
Kirchhoff's Voltage Law (KVL) states that the sum of all voltages around a closed loop in an electrical circuit is equal to zero. KVL can be expressed mathematically as an equation where the applied voltage equals the sum of all voltage drops around the loop. An example problem was provided to demonstrate applying KVL with an equation to solve for unknown voltages in a circuit.
Registers are groups of flip-flops that store binary data. An n-bit register contains n flip-flops and can store 2^n different states. Registers are used to store and provide digital data to logic circuits. There are different types of registers including shift registers. Shift registers can transfer data in serial-in serial-out, serial-in parallel-out, parallel-in serial-out, and parallel-in parallel-out modes. Counters are registers that increment their stored value on each clock pulse and are used to count events.
The document discusses several topics in electrostatics including electric potential, potential difference, equipotential surfaces, Gauss's law, and applications of Gauss's law. Gauss's law states that the electric flux through any closed surface is equal to the enclosed charge divided by the permittivity of free space. This relationship can be used to derive Coulomb's law and calculate electric fields due to various charge distributions like line charges, plane sheets of charge, and spherical shells.
Double Side band Suppressed carrier (DSB-SC) Modulation and Demodulation.SAiFul IslAm
This document describes an experiment on double sideband suppressed carrier (DSB-SC) modulation and demodulation performed by electrical engineering students at the University of Asia Pacific. The objectives were to observe DSB-SC modulation using an MC1496 modulator and examine synchronous demodulation of DSB-SC signals. The experiment involved generating a message signal, carrier signal, and DSB-SC modulated signal. A balanced modulator was used to produce the DSB-SC signal. Synchronous demodulation using a balanced multiplier, low-pass filter, and same carrier signal as the modulator recovered the original message signal from the DSB-SC signal. The students observed input and output waveforms and discussed the circuit connections and results
Ampere's law relates the magnetic field around a closed loop to the electric current passing through the loop. It states that the line integral of the magnetic field around the loop equals the net current passing through the loop times the permeability of free space. The document provides examples of using Ampere's law to calculate magnetic fields for various current carrying wire configurations, including inside and outside a long straight wire, inside a solenoid, and inside and outside a toroidal coil.
This presentation covers scalar quantity, vector quantity, addition of vectors & multiplication of vector. I hope this PPT will be helpful for Instructors as well as students.
This document summarizes an experiment on diode clipping and clamping circuits. It includes the objectives, equipment used, circuit diagrams of clipping and clamping circuits tested, and results from those circuits. Key findings are: 1) clipping circuits cut off portions of the input signal above or below certain voltage thresholds, while clamping circuits shift the entire signal up or down by a fixed amount. 2) In a clipping circuit, diodes allow the output to follow the input until a threshold is reached, then clamp the output at that level. 3) A clamping circuit uses a capacitor, diode, and resistor to shift the entire signal down by twice the peak input voltage.
1) Alternating current (AC) refers to sinusoidal voltage and current waveforms. AC can be generated from sources like AC generators, wind turbines, hydroelectric power plants, and solar panels.
2) Key characteristics of AC waveforms include instantaneous value, peak amplitude, peak value, peak-to-peak value, period, frequency, phase, and whether they are periodic.
3) Sinusoidal waves can be expressed as v = Vm sin(ωt+θ), where Vm is the peak amplitude, ω is the angular frequency, t is time, and θ is the phase. The phase relationship between two sinusoidal waves indicates whether one leads or lags the other.
The document discusses vector calculus concepts including:
- Vector product has magnitude equal to the area of the parallelogram formed by the vectors and is perpendicular to both vectors.
- Scalar triple product equals the volume of the parallelepiped formed by the three vectors and represents the scalar quantity obtained by multiplying the vectors in a specific order.
- Vector triple product follows the "bac-cab" rule and results in another vector quantity.
This document discusses parallel circuits. It defines parallel circuits as having multiple paths for current to flow and that the voltage is the same across each component. The total resistance of a parallel circuit is smaller than its branches because the overall conductance is the sum of the individual conductances. The current divider rule is used to calculate the current through each resistor in a parallel circuit.
Gauss's law relates the electric flux through a closed surface to the electric charge enclosed by the surface. It can be used to calculate the electric field due to various charge distributions like:
- A point charge, where the electric field is spherically symmetric and directed radially outward.
- An infinite line charge, where the electric field is directed radially outward and its magnitude depends only on the distance from the wire.
- An infinite plane sheet, where the electric field is uniform and perpendicular to the sheet.
- Two parallel charged sheets, where the electric field is zero outside and uniform inside, directed from the positive to negative sheet.
- A charged spherical shell, where the electric field
B.Tech sem I Engineering Physics U-III Chapter 1-THE SPECIAL THEORY OF RELATI...Abhi Hirpara
The document discusses Einstein's theory of special relativity. It provides background on Einstein's two postulates: 1) the laws of physics are the same in all inertial frames of reference, and 2) the speed of light in a vacuum is the same for all observers regardless of their motion. It describes how these postulates led Einstein to develop the Lorentz transformations, which show that time and space are relative between different frames of reference moving at a constant velocity with respect to each other.
This document discusses signals and their classification. It defines signals, analog and digital signals, periodic and aperiodic signals. It also discusses representing signals in Matlab and Simulink. Key signal types covered include exponential, sinusoidal, unit impulse and step functions. Matlab is presented as a tool for programming and analyzing discrete signals while Simulink can be used to model and simulate continuous systems.
This document provides an overview of basic electronics concepts including lattices, semiconductors, diodes, and transistors. It begins by defining lattices and their applications in mathematics. It then discusses superconductors, insulators, intrinsic and extrinsic semiconductors, and the band theory of conduction. Diodes and rectifiers are introduced, including half-wave and full-wave rectification circuits. The document concludes by explaining transistors, including bipolar junction transistors with npn and pnp configurations and their characteristics curves. Transistors are shown to have applications as amplifiers and switches in devices like LED spotlights and single transistor radios.
This document summarizes key concepts about transformers:
1) Transformers transfer electrical energy from one voltage level to another through a magnetic field without changing frequency. They have a primary and secondary winding wound around an iron core.
2) An AC voltage applied to the primary induces a voltage in the secondary according to Faraday's Law of induction. The ratio of voltages is determined by the ratio of turns in the windings.
3) Real transformers have losses that are modeled in an equivalent circuit including resistances of the windings and core and a magnetizing reactance. Impedances can be transferred between windings using the turns ratio.
This document summarizes key concepts about transformers:
1) Transformers transfer electrical energy from one voltage level to another through magnetic coupling between primary and secondary coils. They do not directly convert electrical to mechanical energy.
2) An ideal transformer transfers power without losses, but real transformers have resistive losses in their coils and core that reduce efficiency.
3) The voltage and current ratios between primary and secondary coils are determined by their relative turn ratios; this relationship allows impedances to be transferred between sides.
A transformer is a device that changes alternating current (ac) electric power at one voltage level to ac electric power at another voltage level through the action of a magnetic field. An ideal transformer is a lossless device that transfers power efficiently between its two windings. A real transformer is modeled using an equivalent circuit that accounts for power losses, including copper losses, eddy current losses, hysteresis losses, and leakage fluxes. The parameters of the equivalent circuit can be determined experimentally using open-circuit and short-circuit tests.
Transformers (Especially For 12th Std)Atit Gaonkar
It Is The One Which Will Help A Student To Recall or Study about Transformer.
The Principle, Constructions, Working, Ideal Transformer, Leakages, Efficiency, Cores, Related Solved Problems. etc. are readily available in this power-point.
A transformer is a device that changes alternating current (ac) electric power at one voltage level to ac power at another voltage level through magnetic induction. It consists of two or more coils wound around a core and linked by a magnetic field. An ideal transformer has no losses and the power input equals the power output. Real transformers have losses due to winding resistance, core losses, and leakage fluxes. The performance of real transformers can be modeled using an equivalent circuit with parameters determined from open-circuit and short-circuit tests. Transformer voltage regulation and efficiency are important performance metrics.
The document discusses power analysis of AC circuits. It defines key concepts such as effective value, apparent power, power factor, complex power and power triangle. It provides formulas to calculate average power, reactive power and apparent power for single and multiple loads. As an example, it calculates the total average power, reactive power and complex power for a fast food restaurant with two loads - one drawing 24 kW at 0.8 leading PF and the other drawing 20 kVAR at 0.7 lagging PF. The total powers work out to be 24 kW for average power, 2 kVAR for reactive power and 30 kVA for apparent/complex power.
This document provides information about the Basic Electrical Engineering course offered by the EC department at VCET PUTTUR. The course code is 18ELE23 and it is worth 3 credits. The course aims to teach students about DC and AC electric circuits, transformers, DC machines, synchronous generators, and electrical wiring. The course is divided into 5 modules covering topics such as DC circuits, single and 3-phase AC circuits, transformers, DC motors and generators, and induction motors. The document also provides information on electric circuits, Ohm's law, series and parallel resistances, and single-phase AC circuits including definitions of terms like frequency, time period, effective value, and form factor. It includes example problems related to AC circuits.
This document provides definitions and explanations of key concepts in electricity. It defines electricity as the movement of charged particles, describes how wired electricity works with electrons moving through wires, and distinguishes between direct and alternating current. Key concepts explained include voltage, current, resistance, capacitors, inductors, transformers, and how alternating current grids work at both the transmission and household levels.
This document discusses electromagnetic induction and how it is used to generate alternating current (AC) in generators. It explains that rotating coils within a magnetic field generate an electromotive force (EMF) that produces a current. The current flows back and forth as the coils rotate, making it an alternating current. It describes the key components of a basic AC generator, including the coil, slip rings, and brushes. The output is a sinusoidal waveform where the current is maximum when the coil's motion cuts the most magnetic field lines per unit time. It also discusses how transformers are used to change AC voltages by using the principle of electromagnetic induction.
factors affecting internal resistance/emf of the cellYogesh Baghel
This document discusses internal resistance, electromotive force (EMF), and using an oscilloscope to measure voltage and frequency from a signal generator. It explains how to create batteries from lemons and measure their internal resistance. It also covers how oscilloscopes can be used as voltmeters to measure DC and AC voltage, and how they can measure frequency. The document contains questions about batteries, internal resistance, EMF, RMS voltage, AC power, and using an oscilloscope.
Aishwarya Shah completed a multi-disciplinary project on electricity for class 10. The project covered definitions of electricity, electric current, potential difference, electromotive force, electric circuits and components, measuring current and voltage, Ohm's law, factors affecting resistance, and combinations of resistors. It also discussed the heating effect of electricity and its applications. The project explained key concepts through definitions, diagrams, equations, and examples. Aishwarya thanked her teacher for the opportunity and hoped the effort was appreciated.
lec 8 and 9 single phase transformer.pptxssuser76a9bc
The document discusses single phase transformers, including their construction, operation principle, ideal and non-ideal models, and methods to determine component values. A transformer transfers energy between circuits through electromagnetic induction. It has a core made of laminated silicon steel and windings wrapped around the core. Varying the primary current induces a voltage in the secondary according to Faraday's law of induction and the turns ratio. Real transformers have losses accounted for in their equivalent circuit model, which is used to analyze power flow and regulation. Component values are found through short-circuit, open-circuit, and DC tests.
This document provides definitions and explanations of key concepts in electricity. It discusses the basics of electric current, direct current versus alternating current, voltage, resistance, capacitors, inductors, transformers, and the development of alternating current power grids and transmission. Key points covered include how wired electricity works through the movement of electrons, definitions of voltage, current, resistance, and power. Circuit elements like resistors, capacitors and inductors are also defined.
The document summarizes the history and development of electrical power distribution systems. It discusses:
1. The first system developed by Edison in the 1880s transmitted direct current (DC) at low voltages, requiring high currents. This led to significant energy losses.
2. Tesla proposed the second generation system still in use today, which generates alternating current (AC) at high voltages for transmission to reduce losses. Transformers are used to step up voltage for transmission and step down for use, reducing losses compared to DC transmission.
3. Transformers convert one AC voltage to another through electromagnetic induction using coils wrapped around a ferromagnetic core, allowing flexible voltage conversion with minimal energy loss.
- AC power transmission is more economical than DC transmission due to lower line losses and easier fault protection.
- In AC circuits, voltage and current can be represented as phasors to analyze the relationship between instantaneous and average power.
- Reactive power in inductive and capacitive circuits averages to zero over each cycle but increases apparent power. Power factor correction reduces reactive power.
- Three-phase systems are more efficient than single-phase as they transmit more power using three conductors with constant power output. Star and delta connections determine the relationship between phase and line voltages/currents.
- Transformers work on the principle of electromagnetic induction to change the voltage of an alternating current while keeping the current the same. They have a primary coil connected to a power source and a secondary coil where power is output.
- The ratio of turns between the primary and secondary coils determines whether it is a step-up or step-down transformer. A step-down transformer decreases voltage and increases current while a step-up does the opposite.
- Efficiency is affected by resistance in coils, hysteresis losses in the core, eddy currents, and magnetic flux leakage. Laminated cores and thicker wire can improve efficiency.
The document discusses alternating current (AC) and provides details about its key characteristics:
1) AC electricity alternates direction periodically in a back-and-forth motion, unlike direct current which flows in one direction.
2) The instantaneous value of AC varies sinusoidally over time between a maximum and minimum value.
3) Common applications of AC include power transmission and use in homes/businesses due to advantages like easy voltage transformation.
The document discusses alternating current (AC) and provides details about its key characteristics:
1) AC electricity alternates direction periodically in a back-and-forth motion, unlike direct current which flows in one direction.
2) The instantaneous value of AC varies sinusoidally over time between a maximum and minimum value.
3) Common applications of AC include transmission of electricity over long distances using transformers and conversion to DC using rectifiers.
1) Charge is the electrical property of atomic particles that composes matter. It can be negative or positive and is measured in coulombs.
2) Current is the flow of charge or electrons through a conducting material. It is measured in amperes.
3) Alternating current periodically changes its magnitude and direction, unlike direct current which flows in only one direction. It is the type of electric current used in power grids and appliances.
Similar to Wk 17 p1 wk 18-p6_24.1-24.4_alternating currents (20)
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Wk 17 p1 wk 18-p6_24.1-24.4_alternating currents
1. Alternating Current
24. Alternating Currents
Content
24.1 Characteristics of alternating currents
24.2 The transformer
24.3 Transmission of electrical energy
24.4 Rectification
Learning Outcomes
Candidates should be able to:
(a) show an understanding of and use the terms period, frequency, peak value
and root-mean-square value as applied to an alternating current or voltage.
* (b) deduce that the mean power in a resistive load is half the maximum power
for a sinusoidal alternating current.
* (c) represent a sinusoidally alternating current or voltage by an equation of the
form x = xosinωt.
2. (d) distinguish between r.m.s. and peak values and recall and solve problems using the
relationship Irms = Io/√2 for the sinusoidal case.
(e) show an understanding of the principle of operation of a simple iron-cored
transformer and recall and solve problems using Ns/Np = Vs/Vp = Ip /Is for an ideal
transformer.
(f) show an appreciation of the scientific and economic advantages of alternating
current and of high voltages for the transmission of electrical energy.
* (g) distinguish graphically between half-wave and full-wave rectification.
(h) explain the use of a single diode for the half-wave rectification of an alternating
current.
(i) explain the use of four diodes (bridge rectifier) for the full-wave rectification of an
alternating current.
* (j) analyse the effect of a single capacitor in smoothing, including the effect of the
value of capacitance in relation to the load resistance.
3. Direct current
• When a battery is connected to a circuit, the current flows steadily
in one direction
• This sort of current is known as direct current or in short d.c.
• However the domestic and industrial electricity supply produced
by generators at a power station is one which does not use direct
current but alternating current
Direct current Alternating current
0 Time
4. Alternating currents
• An alternating current (a.c.) or voltage is one which continuously
reverses its direction of flow after a certain interval of time, that is, it
varies in magnitude and direction with time.
• The amplitude or magnitude of such a current (for a a.c of sinusoidal wave
form) at any time frame is as follows:
I = I0sin t I = I0sin 2ft I = I0sin 2(t/T)
where, I = current at any time t in amperes A
I0 = peak current
= 2f, angular frequency, rad s-1
f = /2, frequency in Hz or no. of cycles per second
T = 1/f = period in seconds
• The time for one complete alternation, a cycle, is the period T. The number
of cycles in one second is the frequency f. The frequency of an alternating
current may range from 50 Hz to 100 Hz. For e.m.f., the same formulae
apply
• Sometimes the term peak-to-peak is used which means 2Io or 2Vo i.e. twice
the amplitude value
5. Other forms of alternating currents
The following are some other wave forms of alternating currents produced by specially-
designed electronic circuits:
I or V 1 cycle I or V 1 cycle
I0
t t
T/2 T
Saw-toothed wave Square wave
6. Power in a resistor
• From the picture of a sinosoidal wave although it is clear that the average
value of an alternating current is zero, it does not mean that when an a.c
source is connected to a resistor, no power is generated in the resistor
• Using I = I0sin t and the power P = I2
R generated in a resistance R
P = Io
2
R sin2 t
• Because Io
2 and sin2
t are always positive, the power P is always
positive
• The above expression gives the power at any instant of time, but what is
much more useful is the average or mean power which is the power
generated in the resistor
7. Root-Mean-Square (r.m.s.) value of an A.C.
• The root-mean-square value of an alternating current is defined as the equivalent
value of the steady d.c. which would dissipate energy at the same average rate in a
given resistance. It is also called the effective value of an a.c.
• A direct current with a value of I equal to the r.m.s current Irms of an a.c. circuit
will produce exactly the same heating effect in a resistor
• Because the current in an a.c. changes direction many times in a second, the
effective value of the current (Irms or Ir) is thus an average value of currents I
throughout one whole cycle of the current’s sinusoidal wave.
Pac = Idc
2R = Ir
2R
Ir
2 = average value of I2
= I0
2/2
Ir = I0/2 = I0/1.414 = 0.707 I0
• Similarly,Vr = V0/2 V0 = 2 Vr
• In specifying a domestic supply voltage, it is the r.m.s. value that is quoted
• If the voltage of an a.c. mains supply is 240 V (r.m.s.), an electrical appliance must be
able to stand up to a peak value of 2 x 240 V (= 339.4 V) in order for it to be able to
be used on the mains.
• The r.m.s value of the current or voltage is that value of the direct current or
voltage that would produce heat at the same rate in a resistor
8. R.m.s. the mathematics
The r.m.s value ofa function f(x) within the range a x b is givenby:
2
1
2
)(
1
dxxf
ab
b
a
If f(x) = sin xand integrating for xbetween x= 0 and x=
2
gives
2
1
2
2
0
sin
02/
1
dxx
=
2
1
2
0
)2cos1(
2
dxx
=
2
1
2
1
=
2
1
9. Mean power of a.c.
• Mean power Pac = Ir
2R = (I0/2)2.R = 1/2 ( I0
2R ) = 1/2 P0
• That is, mean power is half the maximum power or peak power for an a.c. passing
through a resistive load.
V = V0.sin t I = I0.sin t
0 t
P
I0
2
R P =( I0
2
.sin2
t).R
1/2 I0
2
R
0 t
10. Example
• A 1.5 kW heater is connected to the domestic supply which is quoted as 240
V. Calculate the peak current in the heater, and its resistance.
Solution
From P = Vrms x Irms , Irms = 1500/240 = 6.3 A
Hence peak current I0 is 6.3 x 1.414 = 8.8 A
and the resistance R = Vrms/Irms = 240/6.3 = 38 ohms
11. Transformer principles
• A transformer is a device used for stepping-up (or down) an a.c. supply
voltage using the Mutual Induction Principle. Basically it consists of two coils
of wires, one called the primary and the other the secondary, of an
appropriate number of turns. These coils normally wind round a laminated
soft-iron core for better permeability of the magnetic field or flux linkage of
the two coils giving a higher flux.
• When an alternating voltage Vp is applied to the primary coil, it sets up a
fluctuating magnetic field which in turn induces a back e.m.f. Ep. The current
Ip in the primary coil is given by:
Vp - Ep = Ip.Rp ( Rp = primary coil resistance )
As p = Np
Ep = dp/dt = Npd/dt
• For an ideal transformer, Rp 0 giving Vp Ep.
i.e. Vp = Npd/dt
where Np is the number of turns in the primary coil and the flux in the iron
core linking the coils.
12. cont..
• At the secondary coil where it is connected to a load, the output voltage Vs is
given by:
Vs = Es - IsRs ( Rs = secondary coil resistance )
and Es is the mutually induced e.m.f. in the secondary coil.
Es = ds/dt = Nsd/dt
• Again, for an ideal transformer, Rs 0 giving Vs Es.
i.e. Vs = Nsd/dt
Vs/Vp = Ns/Np
13. cont..
• The voltage Vp applied to the primary, from the source current, is used simply
in overcoming the back-e.m.f. Ep., if we neglect the resistance of the wire.
Therefore, it is equal in magnitude to Ep. (This is analogous to saying, in
mechanics, that action and reaction are equal and opposite.)
• For an ideal transformer (i.e. 100% efficient), the power supply in the primary
coil will be fully transferred to the secondary output.
Hence: VpIp = VsIs or Vs/Vp = Ip/Is
• Thus for an ideal transformer,
• So the transformer steps voltage up or down according to its 'turns-ratio'.
The voltage may be stepped up from 25,000 to 400,000 volts for high-
tension transmission and stepped down from 240 V to 6 V for ringing bells.
s
p
p
s
p
s
I
I
N
N
V
V
primaryinvoltageApplied
secondaryine.m.f.Induced
14. Energy Losses and Efficiency in Transformer
• There are 4 main losses:
(a)Heat is lost in coils (primary and secondary) due to resistance of the
windings. For transformers handling very high electrical power, the windings
are made of very thick wires to reduce power lost as heat. The windings are
insulated and immersed in oil for cooling purpose.
(b)The alternating flux in the primary induces eddy current in the iron core that
causes heat loss.
(c)The magnetisation and demagnetisation of the iron core give rise to the
hysteresis loss and hence power loss.
(d)When the flux produced by the primary is not 100% linked to the secondary,
then the input electrical power will not be fully transferred to the secondary
output as flux leakage occurs. (does not pass through iron core).
• Efficiency = (power in secondary/power in primary) x 100%
15. Electrical power transmission
• When electricity is transmitted from a source, such as a power station to a
distant load, such as a factory or household, power is lost as Joule heating
I2R through the transmission cables where R is the total resistance of the
cables.
• Suppose the electrical power generated Pgen is to be delivered at a p.d. of V
by the supply lines of total resistance R. The current in the supply line will
be:
I = Pgen/V
• Hence, the power loss as heat will be given by:
Ploss = I2R = (Pgen/V)2R
• The equation indicates that for lower power loss, V has to be high in value.
Hence for economic reasons, transmission must be at high V and low I state.
But a low I means a thicker and costlier cable while higher voltage will result
in higher insulation cost. The result is a solution taking cable resistance, the
voltage of transfer and insulation cost into consideration.
16. Example
(1) A power station generates a power of 200 MW at a potential difference of
400 kV. This input power is transmitted to a distant town through a pair of
overhead lines whose total resistance is 5.0 .
(a) Calculate (i) the current in the wires (ii) the voltage between the terminals
at the far end of the lines.
(b) State, in each case, a reason why the designers of the transmission
system did not choose an input voltage of: (i) 240 V (ii) 2.0 MV.
(c) (i) Give one example of a situation where it is essential to route power
cables underground. (ii) State one disadvantage, other than high cost, of
laying power cables underground.
Solution
(a) (i) I = P/V = 200 x 106/(400 X 103) = 500 A
(ii) Voltage drop = IR = 500 x 5.0 = 2500 = 2.5 kV
Voltage between terminals at far end of lines = 400 – 2.5 = 397.5 kV
(b) (i) Current high, hence requires thick expensive cables.
(ii) Need tall pylons, wide cables’ spacing, costly insulation, possible
discharge in air.
(c) (i) Airfields; wide stretches of water.
(ii) Difficult to dissipate heat; insulation problems; risk of damage by
digger; difficulty of access if faults arise; biological effects of
electric/magnetic fields/radiation from currents near ground level.
17. Electrocution
• Electrocution is actually due to the amount of current that flows through the
body.
• The amount of current depends on the resistance offered by the person
between the wire and the earth.
• A current of 0.1 A is able to cause death due to fibrillation (uncontrolled
contractions of the heart).
• People touching live wires may get their hand stuck to the wire due to
contraction of the muscles. It is therefore current, not voltage, which is
dangerous.
18. Rectification
• A.C. is important and useful in power generation and distribution since a.c.
can be stepped up for minimum power-loss transmission.
• For electrical and electronic devices operating on d.c. sources only (e.g.
radio, television, computers etc.), rectification of the a.c. (i.e. to change it to
d.c.) is necessary through use of appropriate rectifiers (diodes)
• Alternating current can be converted to direct current (i.e. rectified) by
making use of devices which conduct appreciable amounts of current in one
direction only. Such devices are called rectifiers and include thermionic
diodes, metal rectifiers and semiconductor diodes.
• A rectifier is an electrical device which converts alternating current to
direct current, a process known as rectification. Rectifiers are used as
components of power supplies and as detectors of radio signals.
• Rectifiers may be made of solid state diodes, vacuum tube diodes, mercury
arc valves, and other technologies.
19. cont..
• A rectifier is said to be forward-biased when it is
connected to a power supply in such a way that it
conducts. If connected the other way, the rectifier is
reverse-biased. The current-voltage curve of a
typical rectifier is shown below:
Current throughrectifier
Low-resistance when
Forward-biased
O PD across rectifier
High-resistance whenreverse-biased
20. Half-wave rectification by a single diode
• The rectifier conducts only during the
half cycle which means that the output
across the load will consist of only the
positive half-cycles. Although the
output is pulsating, it is unidirectional,
i.e. direct current.
X
Alternating supply Load
Y
Supply PD
O t
PD across
load
O t
21. Full-wave rectification
• It is more satisfactory also to make use of
the negative hal-cycles as well and this can
be achieved by using an arrangement of 4
rectifiers (diodes) known as a bridge
rectifier.
• When P is positive, diodes across PQ and
SR conduct; when R is positive, diodes
across RQ and SP conduct. In each case the
current through the load is in the same
direction – from Q to S. The p.d. across the
load has the form shown below.
• Thus, full-wave rectification allows the
load to draw current from the supply on
each half of each cycle and therefore the
power that can be utilized is double that
achieved with half-wave rectification.
P.D. across
load
O t
22. Smoothing by a single capacitor
• The pulsating unidirectional rectified current output produced by both half-
wave and full-wave rectifiers is still not a good approximation to the steady
direct current required for most electronic equipment
• It can be made more steady (smoothed) by inserting a suitable capacitor in
parallel with the load or across the output terminals of the bridge circuit
• The effect is to reduce the fluctuations in the unidirectional output
• Generally a larger value of the capacitor will give better smoothing although the
more important factor is the resistor-capacitor time-constant
X
Pulsating Smoothing Load Current
Rectified p.d. capacitor
24. cont..
• As the rectifier voltage increases, it charges the capacitor and also supplies current to
the load. At the end of the quarter cycle the capacitor is charged to its peak value Vm of
the rectifier voltage. Following this the rectifier voltage starts to decrease as it enters
the next quarter cycle. This initiates the discharge of the capacitor through the load.
• At points such as A the p.d. across the load has just reached its maximum value. If the
capacitor were not present, the p.d. would start to fall to zero along the broken curve.
However, as soon as the p.d. across the load starts to fall, it becomes less than that
across the capacitor and the capacitor starts to discharge through the load. Since the
charging process causes plate X to be positive, the discharge drives current through the
load in the same direction as it flowed during charging.
P.D. across Smoothed p.d.
load A Ripple
voltage
O time
Unsmoothed half-wave rectified p.d.
P.D. across
Load A Smoothed p.d.
O time
Unsmoothed half-wave rectified p.d.