1) The document summarizes a physics lecture on induction, electromagnetic oscillations, and LC circuits.
2) Key topics included Faraday's law of induction, Lenz's law, inductance, RL circuits, LC circuits, and deriving the oscillation frequency of LC circuits.
3) Damped oscillations in non-ideal LC circuits were also discussed, where resistance causes the amplitude of oscillations to decrease over time.
1. The document provides a supplemental study guide for physics II covering key concepts in electricity and magnetism, including that electric fields are produced by charges and magnetic fields by moving charges.
2. It defines important terms like voltage, capacitors, current, direct and alternating current, and magnetic fields from current carrying wires. Concepts like Coulomb's law, capacitance, and electromagnetic induction are also explained.
3. Examples and formulas are given for forces on charges and wires in magnetic fields, torque on current loops, magnetic flux, inductors, and resonance in RLC circuits to help students visualize and understand topics in electricity and magnetism.
1. Michael Faraday discovered electromagnetic induction in 1831 when he found that a changing magnetic field can generate an electric current.
2. According to Faraday's laws of electromagnetic induction, a changing magnetic flux induces an electromotive force (emf) in a circuit. The magnitude of the induced emf is directly proportional to the rate of change of magnetic flux through the circuit.
3. Lenz's law states that the direction of the induced current is such that it creates its own magnetic field to oppose the original change in magnetic flux that created it.
The document is a physics project report submitted by Arpita Nandi to her teacher Akash Baidya. In the acknowledgement, Arpita thanks Akash for his guidance and for providing an interesting physics project topic. She conducted an experiment to study how the self-inductance of a coil depends on various factors. The experiment involved measuring current and bulb brightness in a circuit containing a coil at different frequencies both with and without an iron core inside the coil. Arpita concluded that self-inductance increases when an iron core is inserted or frequency is decreased.
1. The document discusses key concepts in electricity including current, charge, resistance, Ohm's law, alternating current, direct current, and Coulomb's law.
2. Current is defined as the flow of electric charge and is measured in amperes. Resistance is a measure of how an object opposes the passage of electric current.
3. Ohm's law states that current is directly proportional to voltage and inversely proportional to resistance. Coulomb's law describes the quantitative relationship between electric charges and the electric force between them.
Faraday's laws of electromagnetic induction describe how a changing magnetic field can induce an electromotive force (EMF) in a conductor. This is the operating principle behind electric generators and transformers. The document discusses Faraday's experiments demonstrating electromagnetic induction, his laws, self and mutual inductance, generation of sinusoidal voltages, phasor representation, and introduction to three-phase systems and electric grids. Key points covered include Faraday's law of induction, the relationship between induced EMF and rate of change of magnetic flux, how inductance opposes changes in current, and generation of sinusoidal AC voltages through rotating coils in magnetic fields.
1) An inductor opposes changes in current through self-induction, generating a counter-EMF when current increases or decreases. This causes the current in an AC inductive circuit to lag 90 degrees behind the voltage.
2) Inductive reactance represents an inductor's opposition to AC current, and increases with frequency and inductance. It can be calculated using XL=2πfL.
3) A purely inductive AC circuit does not consume any power on average, as energy stored in the magnetic field during one half of the cycle is returned during the other half.
The document discusses the basics of electricity including:
- Electrons flow through an atom's nucleus in orbits and electricity is the flow of electrons from atom to atom in a conductor.
- Current or amperage refers to the electrical flow in a circuit and is measured in amps. Resistance opposes the flow of current and is measured in ohms.
- There are two types of current - direct current (DC) which flows in one direction, and alternating current (AC) which flows back and forth as the polarity alternates.
- Transformers use changing magnetic fields to induce voltage in another coil and allow voltage conversion but cannot be used with direct current which produces a static magnetic field.
This document is a physics investigatory project on self-inductance completed by Isha Saxena of Class IIX at Nosegay Senior Secondary School under the guidance of Mr. Rajan. The project examines how the self-inductance of a coil depends on factors like the number of turns in the coil and the material of the core. The experiment involves measuring the current through and brightness of a bulb connected in series with a coil of varying turns and core materials when powered by an AC source of changing frequency. The results show that self-inductance increases with the number of turns and permeability of the core material.
1. The document provides a supplemental study guide for physics II covering key concepts in electricity and magnetism, including that electric fields are produced by charges and magnetic fields by moving charges.
2. It defines important terms like voltage, capacitors, current, direct and alternating current, and magnetic fields from current carrying wires. Concepts like Coulomb's law, capacitance, and electromagnetic induction are also explained.
3. Examples and formulas are given for forces on charges and wires in magnetic fields, torque on current loops, magnetic flux, inductors, and resonance in RLC circuits to help students visualize and understand topics in electricity and magnetism.
1. Michael Faraday discovered electromagnetic induction in 1831 when he found that a changing magnetic field can generate an electric current.
2. According to Faraday's laws of electromagnetic induction, a changing magnetic flux induces an electromotive force (emf) in a circuit. The magnitude of the induced emf is directly proportional to the rate of change of magnetic flux through the circuit.
3. Lenz's law states that the direction of the induced current is such that it creates its own magnetic field to oppose the original change in magnetic flux that created it.
The document is a physics project report submitted by Arpita Nandi to her teacher Akash Baidya. In the acknowledgement, Arpita thanks Akash for his guidance and for providing an interesting physics project topic. She conducted an experiment to study how the self-inductance of a coil depends on various factors. The experiment involved measuring current and bulb brightness in a circuit containing a coil at different frequencies both with and without an iron core inside the coil. Arpita concluded that self-inductance increases when an iron core is inserted or frequency is decreased.
1. The document discusses key concepts in electricity including current, charge, resistance, Ohm's law, alternating current, direct current, and Coulomb's law.
2. Current is defined as the flow of electric charge and is measured in amperes. Resistance is a measure of how an object opposes the passage of electric current.
3. Ohm's law states that current is directly proportional to voltage and inversely proportional to resistance. Coulomb's law describes the quantitative relationship between electric charges and the electric force between them.
Faraday's laws of electromagnetic induction describe how a changing magnetic field can induce an electromotive force (EMF) in a conductor. This is the operating principle behind electric generators and transformers. The document discusses Faraday's experiments demonstrating electromagnetic induction, his laws, self and mutual inductance, generation of sinusoidal voltages, phasor representation, and introduction to three-phase systems and electric grids. Key points covered include Faraday's law of induction, the relationship between induced EMF and rate of change of magnetic flux, how inductance opposes changes in current, and generation of sinusoidal AC voltages through rotating coils in magnetic fields.
1) An inductor opposes changes in current through self-induction, generating a counter-EMF when current increases or decreases. This causes the current in an AC inductive circuit to lag 90 degrees behind the voltage.
2) Inductive reactance represents an inductor's opposition to AC current, and increases with frequency and inductance. It can be calculated using XL=2πfL.
3) A purely inductive AC circuit does not consume any power on average, as energy stored in the magnetic field during one half of the cycle is returned during the other half.
The document discusses the basics of electricity including:
- Electrons flow through an atom's nucleus in orbits and electricity is the flow of electrons from atom to atom in a conductor.
- Current or amperage refers to the electrical flow in a circuit and is measured in amps. Resistance opposes the flow of current and is measured in ohms.
- There are two types of current - direct current (DC) which flows in one direction, and alternating current (AC) which flows back and forth as the polarity alternates.
- Transformers use changing magnetic fields to induce voltage in another coil and allow voltage conversion but cannot be used with direct current which produces a static magnetic field.
This document is a physics investigatory project on self-inductance completed by Isha Saxena of Class IIX at Nosegay Senior Secondary School under the guidance of Mr. Rajan. The project examines how the self-inductance of a coil depends on factors like the number of turns in the coil and the material of the core. The experiment involves measuring the current through and brightness of a bulb connected in series with a coil of varying turns and core materials when powered by an AC source of changing frequency. The results show that self-inductance increases with the number of turns and permeability of the core material.
The document discusses Faraday's law of induction and electromagnetic induction. It provides an example of calculating the magnetic flux through a planar area. It then analyzes the example, finding the induced EMF and induced current in the circuit. It explains that if the coil was made of an insulating material instead, the induced EMF would remain the same but the induced current would be lower due to the higher resistance.
This document contains the questions and answers from an experiment (Experiment No. A1) involving self-assessment on electrical concepts. It includes 61 questions on topics like the definition of electric current and its SI unit, resistance and its unit, ampere, ohm, drift velocity of electrons, Ohm's law, types of cells, internal resistance, short-circuiting, e.m.f., terminal potential drop, factors affecting e.m.f., galvanometers, ammeters, voltmeters, resistances in series and parallel, and properties of conductors and insulators. The responses provide definitions, explanations, examples and relationships between different electrical quantities.
Transformers operate by exploiting the principle of mutual inductance between two coils. They are used to convert alternating current (AC) voltages from one level to another. An ideal transformer consists of two coils wound on a common magnetic core, with no direct electrical connection between them. Current flowing through the primary coil produces a changing magnetic flux that induces a voltage in the secondary coil. Transformers are widely used in power distribution systems to increase or decrease voltages as needed.
1) The document discusses self-induction and back emf in circuits containing coils or inductors. When the current through a coil changes, it produces a back emf opposing the change due to Lenz's law.
2) It also describes how transformers work using mutual induction between two coils. The primary coil is connected to a changing current that induces a current in the secondary coil.
3) Transformers can be used to change voltages by adjusting the turn ratios of the coils. They allow efficient long-distance power transmission by stepping voltages up for transmission and down for usage.
This document provides an introduction to basic electric and magnetic circuits. It begins by describing a simple circuit with a battery, wire, switch and lightbulb. It then discusses how such circuits can be modeled using idealized components like constant voltage sources and resistors. The document goes on to define several key electrical concepts including charge, current, Kirchhoff's current and voltage laws, voltage, and power. Kirchhoff's laws state that the algebraic sum of currents at any node is zero, and the algebraic sum of voltages around any closed loop is zero. These laws form the basis for circuit analysis.
The document is a physics investigatory project report on self-inductance completed by a student. It includes sections on the aim, apparatus, theory, circuit diagram, procedure, observations, result, precautions, and sources of error of the experiment. The experiment aims to study how the self-inductance of a coil depends on factors like the number of turns in the coil, geometry of the coil, and nature of the core material. The student observes changes in current and brightness of a bulb in an AC circuit when inserting an iron core into the coil and varying the frequency of the AC source.
This document discusses magnetic circuits and electromagnetic induction. It covers topics such as magnetic fields, flux, reluctance, magnetomotive force, self and mutual inductance. Key points include:
- Magnetic fields are fundamental to energy conversion in electrical machines.
- Magnetic flux passes through magnetic materials, forming closed loops.
- Electromagnetic induction causes an induced emf when magnetic flux through a coil changes.
- Self and mutual inductance describe the relationship between current, flux linkage, and induced emf in coils.
This document is a student project on electromagnetic induction submitted by Shubham Kourav to his teacher Mrs. Pratiksha Lawana. It includes an introduction to electromagnetic induction, a history of its discovery, experiments conducted by Faraday and Henry, applications of electromagnetic induction including generators and transformers, and concepts such as Lenz's law, eddy currents, and self and mutual induction. The project aims to study electromagnetic induction and contains sections on magnetic flux, Faraday's law, Maxwell's equations, and more.
This document provides an overview of chapter 22 on electromagnetic induction. It discusses key concepts such as magnetic flux, Faraday's law of induction, Lenz's law, and applications including electric generators. The chapter covers how changing magnetic fields can induce emfs and currents in conductors based on Faraday's law. Lenz's law describes how the direction of induced currents will oppose the change that created them. Applications discussed include the reproduction of sound and electric generators.
1. Electric current is produced when electrons flow through a conducting path from a negatively charged end to a positively charged end.
2. A simple electric circuit consists of a power source, conductor, load, and switch. Current (I) is the rate of flow of electric charge (Q) through a cross-sectional area over time and is measured in amperes.
3. Resistance (R) is a measure of how difficult it is for current to pass through a material and is calculated as the ratio between potential difference (V) and current (I). Resistance depends on the material's length, cross-sectional area, and temperature.
1. Electromagnetic induction is the phenomenon by which a changing magnetic field induces an electromotive force (emf) in a conductor. Experiments by Michael Faraday and Joseph Henry in the 1830s demonstrated this effect and established its laws.
2. Faraday's experiments showed that a changing magnetic flux induces a current in a coil. He placed coils inside changing magnetic fields from moving magnets and observed induced currents.
3. Lenz's law defines the direction of induced current: the current flows such that its magnetic field opposes the change that caused it. This ensures the conservation of energy.
- Michael Faraday demonstrated electromagnetic induction by showing that a changing magnetic flux induces an electromotive force (emf) in a circuit. This discovery revolutionized power generation.
- Lenz's law states that the direction of induced current is such that it creates a magnetic field opposing the change in magnetic flux that created it, in accordance with the law of conservation of energy.
- Faraday's laws of electromagnetic induction relate the induced emf to the rate of change of magnetic flux through a circuit. The magnitude of induced emf is directly proportional to the rate of change of magnetic flux.
The research is about (power in oil rig ) after a short description in a basic of electricity and OHM's law , we explained about power in general . at last we searched about the type of power in oil rig we descript (Electric & Mechanical Drilling Rig , Mechanical Drilling Rigs Advantages and Disadvantages , Electric Drilling Rig , Electric Drilling Rig Advantage , DC (SCR) Drilling Rig , AC (VFD) Drilling Rig , AC versus DC Drilling Rig , AC Drilling Rig Advantages , Size according to depth , Typical power range )
This document discusses electromagnetic induction and Faraday's laws of induction. It begins by explaining the relationship between magnetism and electricity, and how changing magnetic flux can induce an electromotive force (emf) in a conductor. It then describes Michael Faraday's experiments in the 1820s and 1830s that led him to formulate his two laws of electromagnetic induction. The first law states that an emf is induced in a conductor whenever the magnetic flux through the conductor changes. The second law relates the magnitude of the induced emf to the rate of change of magnetic flux. The document goes on to discuss examples of dynamically and statically induced emf, and how Lenz's law determines the direction of induced currents. It also covers
Eric dollard introduction to dielectric and magnetic discharges in electrical...PublicLeaker
This document contains two parts. Part I is a summary of Eric Dollard's 1982 work on dielectric and magnetic discharges in electrical windings. It discusses concepts like capacitance, lines of force, energy storage spatially differing between dielectric and magnetic fields, and the limits of zero and infinity resistance. Part II summarizes a 1919 work by J.M. Miller on electrical oscillations in antennae and induction coils.
Eric dollard's introduction to dielectric and magnetic discharges in electric...PublicLeaker
1) The document discusses capacitance and inductance, focusing on lines of force as a way to represent electric and magnetic fields. It explains how energy can be stored spatially in these fields, either between the plates of a capacitor or in the space surrounding a current-carrying conductor.
2) A key point is that the conventional explanations of capacitance are inadequate, and a better analogy is to think of capacitance similarly to inductance, with energy stored in the electric field represented by lines of force.
3) Examples are given of what happens during rapid discharge of an inductor. If the current path is interrupted, resistance becomes infinite and the collapsing field reaches near light speed, potentially producing powerful effects
- Faraday's experiment demonstrated that a changing magnetic field can induce an electric current in a nearby conductor. He showed this by inducing currents in a secondary coil wrapped around a ring using the changing magnetic field from a primary coil with a switch-controlled current.
- Faraday's law of induction states that the induced emf in a circuit is directly proportional to the rate of change of the magnetic flux through the circuit. A changing magnetic field induces currents that oppose the change according to Lenz's law.
- Examples are given demonstrating how Lenz's law predicts the direction of induced currents based on producing a magnetic field that opposes the change causing it.
1. Michael Faraday discovered electromagnetic induction in 1831 through experiments showing that a changing magnetic field can induce an electric current in a nearby conductor.
2. Faraday's law of induction states that the induced electromotive force (emf) in a conductor is equal to the rate of change of magnetic flux through the conductor.
3. This discovery established the basis for technologies such as electric generators, transformers, electric motors, and inductors which are crucial components of modern electric power systems and electronics.
1. Michael Faraday discovered electromagnetic induction in 1831 through experiments showing that a changing magnetic field can induce an electric current in a nearby conductor.
2. Faraday's law of induction states that the induced electromotive force (emf) in a conductor is equal to the rate of change of magnetic flux through the conductor.
3. This discovery established the basis for technologies such as electric generators, transformers, electric motors, and inductors which are crucial components of modern electric power systems and electronics.
This document discusses inductance and inductors. It begins by explaining self-inductance, where a changing current in a circuit induces an opposing electromotive force (emf). This forms the basis of an inductor, which stores energy in its magnetic field. Mutual induction is also described, where a changing magnetic flux from one coil induces an emf in a nearby coil. The document then examines circuits containing inductors and resistors, describing how inductors oppose changes in current. It discusses the time constant of RL circuits and how inductors cause current to change exponentially over time. Finally, it covers energy storage in magnetic fields and oscillations in LC circuits.
The document provides information about patents and the patent system. It discusses what a patent is, how to obtain one, and key aspects of the patenting process. Some key points include:
- A patent provides the owner the right to exclude others from commercially using an invention for 20 years in exchange for publicly disclosing the invention.
- To be patentable, an invention must be new, non-obvious, and industrially applicable.
- The patenting process involves conducting a prior art search, filing a patent application including claims and descriptions, and undergoing examination.
- Ownership of patent rights for employee or contractor inventions can vary depending on contracts and national laws.
The document discusses Faraday's law of induction and electromagnetic induction. It provides an example of calculating the magnetic flux through a planar area. It then analyzes the example, finding the induced EMF and induced current in the circuit. It explains that if the coil was made of an insulating material instead, the induced EMF would remain the same but the induced current would be lower due to the higher resistance.
This document contains the questions and answers from an experiment (Experiment No. A1) involving self-assessment on electrical concepts. It includes 61 questions on topics like the definition of electric current and its SI unit, resistance and its unit, ampere, ohm, drift velocity of electrons, Ohm's law, types of cells, internal resistance, short-circuiting, e.m.f., terminal potential drop, factors affecting e.m.f., galvanometers, ammeters, voltmeters, resistances in series and parallel, and properties of conductors and insulators. The responses provide definitions, explanations, examples and relationships between different electrical quantities.
Transformers operate by exploiting the principle of mutual inductance between two coils. They are used to convert alternating current (AC) voltages from one level to another. An ideal transformer consists of two coils wound on a common magnetic core, with no direct electrical connection between them. Current flowing through the primary coil produces a changing magnetic flux that induces a voltage in the secondary coil. Transformers are widely used in power distribution systems to increase or decrease voltages as needed.
1) The document discusses self-induction and back emf in circuits containing coils or inductors. When the current through a coil changes, it produces a back emf opposing the change due to Lenz's law.
2) It also describes how transformers work using mutual induction between two coils. The primary coil is connected to a changing current that induces a current in the secondary coil.
3) Transformers can be used to change voltages by adjusting the turn ratios of the coils. They allow efficient long-distance power transmission by stepping voltages up for transmission and down for usage.
This document provides an introduction to basic electric and magnetic circuits. It begins by describing a simple circuit with a battery, wire, switch and lightbulb. It then discusses how such circuits can be modeled using idealized components like constant voltage sources and resistors. The document goes on to define several key electrical concepts including charge, current, Kirchhoff's current and voltage laws, voltage, and power. Kirchhoff's laws state that the algebraic sum of currents at any node is zero, and the algebraic sum of voltages around any closed loop is zero. These laws form the basis for circuit analysis.
The document is a physics investigatory project report on self-inductance completed by a student. It includes sections on the aim, apparatus, theory, circuit diagram, procedure, observations, result, precautions, and sources of error of the experiment. The experiment aims to study how the self-inductance of a coil depends on factors like the number of turns in the coil, geometry of the coil, and nature of the core material. The student observes changes in current and brightness of a bulb in an AC circuit when inserting an iron core into the coil and varying the frequency of the AC source.
This document discusses magnetic circuits and electromagnetic induction. It covers topics such as magnetic fields, flux, reluctance, magnetomotive force, self and mutual inductance. Key points include:
- Magnetic fields are fundamental to energy conversion in electrical machines.
- Magnetic flux passes through magnetic materials, forming closed loops.
- Electromagnetic induction causes an induced emf when magnetic flux through a coil changes.
- Self and mutual inductance describe the relationship between current, flux linkage, and induced emf in coils.
This document is a student project on electromagnetic induction submitted by Shubham Kourav to his teacher Mrs. Pratiksha Lawana. It includes an introduction to electromagnetic induction, a history of its discovery, experiments conducted by Faraday and Henry, applications of electromagnetic induction including generators and transformers, and concepts such as Lenz's law, eddy currents, and self and mutual induction. The project aims to study electromagnetic induction and contains sections on magnetic flux, Faraday's law, Maxwell's equations, and more.
This document provides an overview of chapter 22 on electromagnetic induction. It discusses key concepts such as magnetic flux, Faraday's law of induction, Lenz's law, and applications including electric generators. The chapter covers how changing magnetic fields can induce emfs and currents in conductors based on Faraday's law. Lenz's law describes how the direction of induced currents will oppose the change that created them. Applications discussed include the reproduction of sound and electric generators.
1. Electric current is produced when electrons flow through a conducting path from a negatively charged end to a positively charged end.
2. A simple electric circuit consists of a power source, conductor, load, and switch. Current (I) is the rate of flow of electric charge (Q) through a cross-sectional area over time and is measured in amperes.
3. Resistance (R) is a measure of how difficult it is for current to pass through a material and is calculated as the ratio between potential difference (V) and current (I). Resistance depends on the material's length, cross-sectional area, and temperature.
1. Electromagnetic induction is the phenomenon by which a changing magnetic field induces an electromotive force (emf) in a conductor. Experiments by Michael Faraday and Joseph Henry in the 1830s demonstrated this effect and established its laws.
2. Faraday's experiments showed that a changing magnetic flux induces a current in a coil. He placed coils inside changing magnetic fields from moving magnets and observed induced currents.
3. Lenz's law defines the direction of induced current: the current flows such that its magnetic field opposes the change that caused it. This ensures the conservation of energy.
- Michael Faraday demonstrated electromagnetic induction by showing that a changing magnetic flux induces an electromotive force (emf) in a circuit. This discovery revolutionized power generation.
- Lenz's law states that the direction of induced current is such that it creates a magnetic field opposing the change in magnetic flux that created it, in accordance with the law of conservation of energy.
- Faraday's laws of electromagnetic induction relate the induced emf to the rate of change of magnetic flux through a circuit. The magnitude of induced emf is directly proportional to the rate of change of magnetic flux.
The research is about (power in oil rig ) after a short description in a basic of electricity and OHM's law , we explained about power in general . at last we searched about the type of power in oil rig we descript (Electric & Mechanical Drilling Rig , Mechanical Drilling Rigs Advantages and Disadvantages , Electric Drilling Rig , Electric Drilling Rig Advantage , DC (SCR) Drilling Rig , AC (VFD) Drilling Rig , AC versus DC Drilling Rig , AC Drilling Rig Advantages , Size according to depth , Typical power range )
This document discusses electromagnetic induction and Faraday's laws of induction. It begins by explaining the relationship between magnetism and electricity, and how changing magnetic flux can induce an electromotive force (emf) in a conductor. It then describes Michael Faraday's experiments in the 1820s and 1830s that led him to formulate his two laws of electromagnetic induction. The first law states that an emf is induced in a conductor whenever the magnetic flux through the conductor changes. The second law relates the magnitude of the induced emf to the rate of change of magnetic flux. The document goes on to discuss examples of dynamically and statically induced emf, and how Lenz's law determines the direction of induced currents. It also covers
Eric dollard introduction to dielectric and magnetic discharges in electrical...PublicLeaker
This document contains two parts. Part I is a summary of Eric Dollard's 1982 work on dielectric and magnetic discharges in electrical windings. It discusses concepts like capacitance, lines of force, energy storage spatially differing between dielectric and magnetic fields, and the limits of zero and infinity resistance. Part II summarizes a 1919 work by J.M. Miller on electrical oscillations in antennae and induction coils.
Eric dollard's introduction to dielectric and magnetic discharges in electric...PublicLeaker
1) The document discusses capacitance and inductance, focusing on lines of force as a way to represent electric and magnetic fields. It explains how energy can be stored spatially in these fields, either between the plates of a capacitor or in the space surrounding a current-carrying conductor.
2) A key point is that the conventional explanations of capacitance are inadequate, and a better analogy is to think of capacitance similarly to inductance, with energy stored in the electric field represented by lines of force.
3) Examples are given of what happens during rapid discharge of an inductor. If the current path is interrupted, resistance becomes infinite and the collapsing field reaches near light speed, potentially producing powerful effects
- Faraday's experiment demonstrated that a changing magnetic field can induce an electric current in a nearby conductor. He showed this by inducing currents in a secondary coil wrapped around a ring using the changing magnetic field from a primary coil with a switch-controlled current.
- Faraday's law of induction states that the induced emf in a circuit is directly proportional to the rate of change of the magnetic flux through the circuit. A changing magnetic field induces currents that oppose the change according to Lenz's law.
- Examples are given demonstrating how Lenz's law predicts the direction of induced currents based on producing a magnetic field that opposes the change causing it.
1. Michael Faraday discovered electromagnetic induction in 1831 through experiments showing that a changing magnetic field can induce an electric current in a nearby conductor.
2. Faraday's law of induction states that the induced electromotive force (emf) in a conductor is equal to the rate of change of magnetic flux through the conductor.
3. This discovery established the basis for technologies such as electric generators, transformers, electric motors, and inductors which are crucial components of modern electric power systems and electronics.
1. Michael Faraday discovered electromagnetic induction in 1831 through experiments showing that a changing magnetic field can induce an electric current in a nearby conductor.
2. Faraday's law of induction states that the induced electromotive force (emf) in a conductor is equal to the rate of change of magnetic flux through the conductor.
3. This discovery established the basis for technologies such as electric generators, transformers, electric motors, and inductors which are crucial components of modern electric power systems and electronics.
This document discusses inductance and inductors. It begins by explaining self-inductance, where a changing current in a circuit induces an opposing electromotive force (emf). This forms the basis of an inductor, which stores energy in its magnetic field. Mutual induction is also described, where a changing magnetic flux from one coil induces an emf in a nearby coil. The document then examines circuits containing inductors and resistors, describing how inductors oppose changes in current. It discusses the time constant of RL circuits and how inductors cause current to change exponentially over time. Finally, it covers energy storage in magnetic fields and oscillations in LC circuits.
The document provides information about patents and the patent system. It discusses what a patent is, how to obtain one, and key aspects of the patenting process. Some key points include:
- A patent provides the owner the right to exclude others from commercially using an invention for 20 years in exchange for publicly disclosing the invention.
- To be patentable, an invention must be new, non-obvious, and industrially applicable.
- The patenting process involves conducting a prior art search, filing a patent application including claims and descriptions, and undergoing examination.
- Ownership of patent rights for employee or contractor inventions can vary depending on contracts and national laws.
This document provides an outline and overview of key concepts related to research ethics. It discusses several important topics:
- The relationship between ethics and success in research. Unethical behavior can stem from ignorance, stress, or a desire for success.
- Common ethical theories used in analyzing research conduct, including consequentialism, deontology, casuistry, and virtue ethics.
- Important ethical codes and guidelines like the Nuremberg Code, which outlines standards for human subjects research.
- Issues that can arise involving students, employees, data collection/presentation, authorship, and obtaining funding.
The document emphasizes teaching ethical standards and providing resources to researchers to help avoid unethical behavior
X-ray diffraction is a technique used to analyze the crystal structure of materials. Wilhelm Röntgen discovered X-rays in 1895, and Max von Laue discovered X-ray diffraction by crystals in 1912. Bragg's law, discovered in 1913, forms the basis for analyzing diffraction patterns to determine crystal structures. While traditionally useful, X-ray diffraction faces challenges in analyzing nanostructures due to their lack of long-range order and increased defects. Advances in detection technology and techniques have helped make X-ray diffraction applicable to characterizing nanomaterials.
The document discusses different types of printers used in computers. It describes impact printers that form characters by striking an inked ribbon against paper, and non-impact printers that form characters without physical contact. It also discusses fully formed character printers where each letter is a complete shape, and dot matrix printers where letters are formed by patterns of dots. The document provides details on drum printers, daisy wheel printers, line printers, and dot matrix printers.
Hinduism is one of the oldest religions in the world with over 900 million followers worldwide. It originated in India and is based on teachings from the Vedas. Unlike other religions, Hinduism has no single founder or single holy text, but rather a collection of scriptures including the Vedas, Upanishads, Puranas, and epics like the Ramayana and Mahabharata. Hindus believe in concepts like dharma, karma, samsara, and moksha. The religion has evolved over thousands of years and continues to adapt, making it difficult to define.
Dr. Shyam Sunder Sharma will give a presentation titled "Digital Learning: A Pathway Towards Education and Research" at the National Seminar on “Challenges and Innovative Measures for Enhancement of Education and Research in HEIs of Rural Areas". The presentation will discuss massive open online courses (MOOCs) and their role in higher education in India, particularly in rural areas. It will cover the education system in India, MOOC platforms like SWAYAM and NPTEL, and how digital learning can help address challenges in higher education like lack of infrastructure and faculty in rural institutions. The presentation argues that digital learning through MOOCs can play a critical role in achieving the goals of
This document summarizes a research project on photoconductivity in nanocomposite films of lead sulfide (PbS) nanocrystals and polystyrene polymer. The researchers observed photoconductivity in these nanocomposite films that is higher than the base materials alone. The objective of the project is to study and elucidate this photoconductivity phenomenon for different compositions of PbS nanoparticles and polymers. Over three years, the researchers will deposit nanocomposite films, characterize the materials, measure electrical properties with and without light exposure, and study the interaction between PbS and the polymer.
Literature Review Basics and Understanding Reference Management.pptxDr Ramhari Poudyal
Three-day training on academic research focuses on analytical tools at United Technical College, supported by the University Grant Commission, Nepal. 24-26 May 2024
ACEP Magazine edition 4th launched on 05.06.2024Rahul
This document provides information about the third edition of the magazine "Sthapatya" published by the Association of Civil Engineers (Practicing) Aurangabad. It includes messages from current and past presidents of ACEP, memories and photos from past ACEP events, information on life time achievement awards given by ACEP, and a technical article on concrete maintenance, repairs and strengthening. The document highlights activities of ACEP and provides a technical educational article for members.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
KuberTENes Birthday Bash Guadalajara - K8sGPT first impressionsVictor Morales
K8sGPT is a tool that analyzes and diagnoses Kubernetes clusters. This presentation was used to share the requirements and dependencies to deploy K8sGPT in a local environment.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
UNLOCKING HEALTHCARE 4.0: NAVIGATING CRITICAL SUCCESS FACTORS FOR EFFECTIVE I...amsjournal
The Fourth Industrial Revolution is transforming industries, including healthcare, by integrating digital,
physical, and biological technologies. This study examines the integration of 4.0 technologies into
healthcare, identifying success factors and challenges through interviews with 70 stakeholders from 33
countries. Healthcare is evolving significantly, with varied objectives across nations aiming to improve
population health. The study explores stakeholders' perceptions on critical success factors, identifying
challenges such as insufficiently trained personnel, organizational silos, and structural barriers to data
exchange. Facilitators for integration include cost reduction initiatives and interoperability policies.
Technologies like IoT, Big Data, AI, Machine Learning, and robotics enhance diagnostics, treatment
precision, and real-time monitoring, reducing errors and optimizing resource utilization. Automation
improves employee satisfaction and patient care, while Blockchain and telemedicine drive cost reductions.
Successful integration requires skilled professionals and supportive policies, promising efficient resource
use, lower error rates, and accelerated processes, leading to optimized global healthcare outcomes.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
1. Physics 121: Electricity &
Magnetism – Lecture 12
Induction II & E-M Oscillations
Dale E. Gary
Wenda Cao
NJIT Physics Department
2. November 7, 2007
Induction Review
Faraday’s Law: A changing
magnetic flux through a coil of
wire induces an EMF in the wire,
proportional to the number of
turns, N.
Lenz’s Law: The direction of the
current driven by the EMF is such
that it creates a magnetic field to
oppose the flux change.
Induction and energy transfer:
The forces on the loop oppose the
motion of the loop, and the power
required to move the loop
provides the electrical power in
the loop.
A changing magnetic field creates
and electric field.
dt
d
N B
Fv
v
F
P
i
P
dt
d
N
s
d
E B
3. November 7, 2007
Induction and Inductance
When we try to run a current
through a coil of wire, the
changing current induces a “back-
EMF” that opposes the current.
That is because the changing
current creates a changing
magnetic field, and the increasing
magnetic flux through the coils of
wire induce an opposing EMF.
We seek a description of this that
depends only on the geometry of
the coils (i.e., independent of the
current through the coil).
We call this the inductance (c.f.
capacitance). It describes the
proportionality between the
current through a coil and the
magnetic flux induced in it.
i
N B
L
V
q
C
Inductance
Inductance units: henry (H), 1 H = 1 T-m2/A
4. November 7, 2007
Inductance of a Solenoid
Consider a solenoid. Recall that the magnetic field inside a solenoid is
The magnetic flux through the solenoid is then
The inductance of the solenoid is then:
Note that this depends only on the geometry. Since N = nl, this can also be
written
in
B 0
inA
dA
B
B 0
lA
n
nA
nl
i
inA
N
i
N
L B 2
0
0
0
l
A
N
L
2
0
l
A
C 0
Compare with capacitance of a capacitor
Number of turns per unit length n = N/l.
Can also write 0= 4p ×107 H/m = 1.257 H/m
Compare with 0 = 8.85 pF/m
5. November 7, 2007
Self-Induction
You should be comfortable with the notion
that a changing current in one loop induces
an EMF in other loop.
You should also be able to appreciate that
if the two loops are part of the same coil,
the induction still occurs—a changing
current in one loop of a coil induces a back-
EMF in another loop of the same coil.
In fact, a changing current in a single loop
induces a back-EMF in itself. This is called
self-induction.
Since for any inductor then
But Faraday’s Law says
i
N
L B
dt
di
L
dt
d
N B
L
dt
d
N
dt
di
L
N
iL
B
B
The self-induced EMF is opposite
to the direction of change of
current
6. November 7, 2007
1. Which statement describes the current through
the inductor below, if the induced EMF is as
shown?
A. Constant and rightward.
B. Constant and leftward.
C. Increasing and rightward.
D. Decreasing and leftward.
E. Increasing and leftward.
Induced EMF in an Inductor
L
7. November 7, 2007
Inductors in Circuits—The RL Circuit
Inductors, or coils, are common in
electrical circuits.
They are made by wrapping insulated
wire around a core, and their main
use is in resonant circuits, or filter
circuits.
Consider the RL circuit, where a
battery with EMF drives a current
around the loop, producing a back
EMF L in the inductor.
Kirchoff’s loop rule gives
Solving this differential equation for i
gives
0
dt
di
L
iR
)
1
( / L
Rt
e
R
i
Rise of current
8. November 7, 2007
RL Circuits
When t is large:
When t is small (zero), i = 0.
The current starts from zero and
increases up to a maximum of
with a time constant given by
The voltage across the resistor is
The voltage across the inductor is
)
1
( / L
Rt
e
R
i
Inductor acts like a wire.
R
i
Inductor acts like an open
circuit.
R
i /
R
L
L
Inductor time constant
RC
C
Capacitor time constant
)
1
( / L
Rt
R e
iR
V
L
Rt
L
Rt
R
L e
e
V
V /
/
)
1
(
Compare:
9. November 7, 2007
2. The three loops below have identical inductors,
resistors, and batteries. Rank them in terms of
inductive time constant, L/R, greatest first.
A. I, then II & III (tie).
B. II, I, III.
C. III & II (tie), then I.
D. III, II, I.
E. II, III, I.
Inductive Time Constant
I. II. III.
10. November 7, 2007
RL Circuits
What happens when the switch is
thrown from a to b?
Kirchoff’s Loop Rule was:
Now it is:
The decay of the current, then, is
given by
Voltage across resistor:
Voltage across inductor:
0
dt
di
L
iR
0
dt
di
L
iR
L
Rt
e
R
i /
Decay of current
L
Rt
R e
iR
V /
L
Rt
L
Rt
L e
e
dt
d
R
L
dt
di
L
V /
/
V
R
(V)
11. November 7, 2007
What is Happening?
When the battery is removed, and the RL series circuit is shorted, the
current keeps flowing in the same direction it was for awhile. How can this
be?
In the case of an RC circuit, we would see the current reverse as the stored
charge flowed off the capacitor. But in the case of an RL circuit the
opposite happens—charge continues to flow in the same direction.
What is happening is that the current tries to drop suddenly, but this
induces an EMF to oppose the change, causing the current to keep flowing
for awhile.
Another way of thinking about it is that the magnetic field that was stored
in the inductor is “collapsing.”
There is energy stored in the magnetic field, and when the source of
current is removed, the energy flows from the magnetic field back into the
circuit.
12. November 7, 2007
Make Before Break Switches
The switch in a circuit like the one at right has to be a
special kind, called a “make before break” switch.
The switch has to make the connection to b before
breaking the connection with a.
If the circuit is allowed to be in the state like this…even
momentarily, midway between a and b, then a big
problem results.
Recall that for a capacitor, when we disconnect the
circuit the charge will merrily stay on the capacitor
indefinitely.
Not so on an inductor. The inductor needs current, i.e.
flowing charge. It CANNOT go immediately to zero.
The collapsing magnetic field in the inductor will force
the current to flow, even when it has no where to go.
The current will flow in this case by jumping the air
gap.
Link to video
You have probably
seen this when
unplugging something
with a motor—a spark
that jumps from the
plug to the socket.
13. November 7, 2007
Example Circuit
This circuit has three identical resistors R = 9
W, and two identical inductors L = 2.0 mH.
The battery has EMF = 18 V.
(a) What is the current i through the battery just
after the switch is closed?
(b) What is the current i through the battery a
long time after the switch is closed?
(c) What is the behavior of the current between
these times? Use Kirchoff’s Loop Rule on
each loop to find out.
A
2
R
i
(acts like open wire)
A
6
3
R
i
(acts like straight wire)
14. November 7, 2007
3. The three loops below have identical inductors,
resistors, and batteries. Rank them in terms of
current through the battery just after the switch
is closed, greatest first.
A. I, II, III.
B. II, I, III.
C. III, I, II.
D. III, II, I.
E. II, III, I.
Current Through Battery 1
I. II. III.
15. November 7, 2007
4. The three loops below have identical inductors,
resistors, and batteries. Rank them in terms of
current through the battery a long time after
the switch is closed, greatest first.
A. I, II, III.
B. II, I, III.
C. III, I, II.
D. III, II, I.
E. II, III, I.
Current Through Battery 2
I. II. III.
16. November 7, 2007
Energy Stored in Magnetic Field
By Kirchoff’s Loop Rule, we have
We can find the power in the circuit by
multiplying by i.
Power is rate that work is done, i.e.
So , or after integration
dt
di
L
iR
dt
di
Li
R
i
i
2
power provided
by battery
power dissipated
in resistor
power stored in
magnetic field
dt
di
Li
dt
dU
P B
di
Li
dUB 2
2
1
Li
UB Energy in magnetic field
2
2
2
1
2
CV
C
q
UE
Recall for electrical energy in a capacitor:
17. November 7, 2007
The LC Circuit
What happens when we make a circuit from
both an inductor and capacitor?
If we first charge the capacitor, and then
disconnect the battery, what will happen to the
charge?
Recall that initially the inductor acts like an open
circuit, so charge does not flow immediately.
However, over longer times the inductor acts
like a simple, straight wire, so charge will
eventually flow off from the capacitor.
As the charge begins to flow, it develops a
magnetic field in the inductor.
19. November 7, 2007
5. What do you think (physically) will happen to
the oscillations over a long time?
A. They will stop after one complete cycle.
B. They will continue forever.
C. They will continue for awhile, and then suddenly stop.
D. They will continue for awhile, but eventually die away.
E. There is not enough information to tell what will happen.
Oscillations Forever?
20. November 7, 2007
Ideal vs. Non-Ideal
In an ideal situation (no resistance in
circuit), these oscillations will go on
forever.
In fact, no circuit is ideal, and all have at
least a little bit of resistance.
In that case, the oscillations get smaller
with time. They are said to be “damped
oscillations.”
Damped Oscillations
This is just like the situation with a
pendulum, which is another kind of
oscillator.
There, the energy oscillation is between
potential energy and kinetic energy.
Spring Animation
mgh
U
2
2
1
mv
K
2
2
1
kx
U 2
2
1
mv
K
l
g
m
k
21. November 7, 2007
Derivation of Oscillation Frequency
We have shown qualitatively that LC circuits act like an oscillator.
We can discover the frequency of oscillation by looking at the
equations governing the total energy.
Since the total energy is constant, the time derivative should be zero:
But and , so making these substitutions:
This is a second-order, homogeneous differential equation, whose
solution is
i.e. the charge varies according to a cosine wave with amplitude Q and
frequency . Check by taking
two time derivatives of charge:
Plug into original equation:
2
2
2
1
2
Li
C
q
U
U
U B
E
0
dt
di
Li
dt
dq
C
q
dt
dU
dt
dq
i 2
2
dt
q
d
dt
di
0
2
2
C
q
dt
q
d
L
)
cos(
t
Q
q
)
sin(
t
Q
dt
dq
)
cos(
2
2
2
t
Q
dt
q
d
0
)
cos(
)
cos(
2
2
2
t
C
Q
t
LQ
C
q
dt
q
d
L 0
1
2
C
L
LC
1
22. November 7, 2007
Example
a) What is the expression for the voltage change across the capacitor in the
circuit below, as a function of time, if L = 30 mH, and C = 100 F, and the
capacitor is fully charged with 0.001 C at time t=0?
First, the angular frequency of oscillation is
Because the voltage across the capacitor is proportional to
the charge, it has the same expression as the charge:
At time t = 0, q = Q, so = 0. Therefore, the full expression for the voltage
across the capacitor is
C
t
Q
C
q
VC
)
cos(
rad/s
4
.
577
)
F
10
)(
H
10
3
(
1
1
4
2
LC
volts
)
577
cos(
1000
)
577
cos(
F
10
C
10
6
3
t
t
VC
23. November 7, 2007
Example, cont’d
b) What is the expression for the current in the circuit?
The current is
c) How long until the capacitor charge is reversed?
That happens after ½ period, where the period is
)
sin( t
Q
dt
dq
i
amps
)
577
sin(
577
.
0
)
577
sin(
)
rad/s
577
)(
C
10
( 3
t
t
i
p
2
1
f
T
ms
44
.
5
2
p
T
24. November 7, 2007
Summary
Inductance (units, henry H) is given by
Inductance of a solenoid is:
EMF, in terms of inductance, is:
RL circuits
Energy in inductor:
LC circuits: total electric + magnetic energy is conserved
i
N
L B
l
A
N
L
2
0
dt
di
L
dt
d
N B
L
(depends only on geometry)
)
1
( / L
Rt
e
R
i
Rise of current
L
Rt
e
R
i /
Decay of current
2
2
1
Li
UB Energy in magnetic field
2
2
2
1
2
Li
C
q
U
U
U B
E
)
cos(
t
Q
q
LC
1
R
L
L
Inductor time constant
Charge equation Current equation Oscillation frequency
)
sin(
t
Q
i