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Electromagnetic waves are propagated by periodic variations of electric and magnetic fields and include radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays. An activity demonstrates that a magnetic field is produced around a coil of insulated copper wire when electric current passes through it, similar to how water waves are created by a disturbance in water. Electromagnetic waves travel at the speed of light in vacuum, do not require a medium, are transverse waves, and have a wide range of frequencies that interact differently with matter.
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Microwaves
This document discusses microwaves and their uses. It begins by noting that James Clerk Maxwell predicted the existence of radio waves in 1864 from his equations. It then discusses how microwaves are generated using specialized vacuum tubes and mentions common devices like magnetrons and klystrons. Examples of applications of microwaves are given as communication, radio, radio astronomy, navigation and power. The most common use of microwaves is in microwave ovens.
Ch7.1klystron
A klystron is a power amplifier tube that uses velocity modulation of an electron beam to produce high power microwave output for radar transmitters. It provides a coherent signal through bunching cavities that regulate the electron speed and excite microwaves in an output cavity. Klystrons are characterized by high power, stability, and gain, and are used in weather radars.
A magnetron is an oscillator that generates microwave energy through interaction of electrons with electric and strong magnetic fields in a crossed-field configuration. Unlike a klystron, it does not provide a coherent signal but has randomly changing phase. Magnetrons have high peak power but lower voltage and are commonly used in inexpensive radars and microwave ovens due
Klystron
A klystron is a vacuum tube that can generate or amplify power at microwave frequencies. It consists of an electron beam emitted from a cathode, two metal cavity resonators, and a collector. In the first cavity, an alternating electric field bunches the electrons. In the second cavity, the electron bunches produce an amplified output signal linked to the cavity's magnetic field oscillations. Klystrons are widely used as microwave amplifiers due to their ability to convert much of the electrons' kinetic energy into electromagnetic energy, producing large signal amplification.
Vande graaff generator
This document discusses static electricity. It explains that static electricity is caused by an imbalance of electrons between two objects, often caused by friction that removes electrons from one object and concentrates them in another. It provides examples like combing hair, which leaves the comb charged from transferred electrons. The document also describes a static electricity generator that uses a rubber belt and metal spheres to separate charges and generate a static charge. Finally, it notes that static buildup can cause sparks as charged objects discharge to nearby metal or the environment.
Klystron 1
Klystron is a specialized linear-beam vacuum tube invented in 1937 by Russell and Sigurd Varian at Stanford University. It works by using an electron gun to produce a beam of electrons, bunching cavities to regulate the electrons into bunches, and an output cavity where the bunches excite microwaves. Klystrons can produce high microwave power and are used in applications such as radar, satellites, television broadcasting, medicine, and particle accelerators.
U9 Cn1
Light is an electromagnetic wave that does not require a medium and travels transverse to the direction of propagation. The electromagnetic spectrum includes all wavelengths of light, which travel at the speed of light in a vacuum or slower in materials. While light behaves as a wave, this document will focus on the direction of the wave, or ray, and how the intensity of light decreases with the inverse square of the distance from the source.
Two cavity klystron
A Klystron is a vacuum tube that can be used either as a generator or as an amplifier or as an oscillator, at microwave frequencies.The Klystron is a linear beam device; that is, the electron flow is in a straight line focused by an axial magnetic field.
Electric Fields
Electric fields are regions where electric forces act and are created by charged particles like electrons and protons. The electric field lines emanate from positive charges and point towards negative charges, and the force on a charge in an electric field is proportional to the charge and strength of the field. Particle accelerators are designed to accelerate charged particles to high speeds using electric fields and gain kinetic energy, and are used in devices like TVs and large collider experiments.
Recommended
Microwaves
This document discusses microwaves and their uses. It begins by noting that James Clerk Maxwell predicted the existence of radio waves in 1864 from his equations. It then discusses how microwaves are generated using specialized vacuum tubes and mentions common devices like magnetrons and klystrons. Examples of applications of microwaves are given as communication, radio, radio astronomy, navigation and power. The most common use of microwaves is in microwave ovens.
Ch7.1klystron
A klystron is a power amplifier tube that uses velocity modulation of an electron beam to produce high power microwave output for radar transmitters. It provides a coherent signal through bunching cavities that regulate the electron speed and excite microwaves in an output cavity. Klystrons are characterized by high power, stability, and gain, and are used in weather radars.
A magnetron is an oscillator that generates microwave energy through interaction of electrons with electric and strong magnetic fields in a crossed-field configuration. Unlike a klystron, it does not provide a coherent signal but has randomly changing phase. Magnetrons have high peak power but lower voltage and are commonly used in inexpensive radars and microwave ovens due
Klystron
A klystron is a vacuum tube that can generate or amplify power at microwave frequencies. It consists of an electron beam emitted from a cathode, two metal cavity resonators, and a collector. In the first cavity, an alternating electric field bunches the electrons. In the second cavity, the electron bunches produce an amplified output signal linked to the cavity's magnetic field oscillations. Klystrons are widely used as microwave amplifiers due to their ability to convert much of the electrons' kinetic energy into electromagnetic energy, producing large signal amplification.
Vande graaff generator
This document discusses static electricity. It explains that static electricity is caused by an imbalance of electrons between two objects, often caused by friction that removes electrons from one object and concentrates them in another. It provides examples like combing hair, which leaves the comb charged from transferred electrons. The document also describes a static electricity generator that uses a rubber belt and metal spheres to separate charges and generate a static charge. Finally, it notes that static buildup can cause sparks as charged objects discharge to nearby metal or the environment.
Klystron 1
Klystron is a specialized linear-beam vacuum tube invented in 1937 by Russell and Sigurd Varian at Stanford University. It works by using an electron gun to produce a beam of electrons, bunching cavities to regulate the electrons into bunches, and an output cavity where the bunches excite microwaves. Klystrons can produce high microwave power and are used in applications such as radar, satellites, television broadcasting, medicine, and particle accelerators.
U9 Cn1
Light is an electromagnetic wave that does not require a medium and travels transverse to the direction of propagation. The electromagnetic spectrum includes all wavelengths of light, which travel at the speed of light in a vacuum or slower in materials. While light behaves as a wave, this document will focus on the direction of the wave, or ray, and how the intensity of light decreases with the inverse square of the distance from the source.
Two cavity klystron
A Klystron is a vacuum tube that can be used either as a generator or as an amplifier or as an oscillator, at microwave frequencies.The Klystron is a linear beam device; that is, the electron flow is in a straight line focused by an axial magnetic field.
Electric Fields
Electric fields are regions where electric forces act and are created by charged particles like electrons and protons. The electric field lines emanate from positive charges and point towards negative charges, and the force on a charge in an electric field is proportional to the charge and strength of the field. Particle accelerators are designed to accelerate charged particles to high speeds using electric fields and gain kinetic energy, and are used in devices like TVs and large collider experiments.
How does an electromagnet work
Both bar magnets and electromagnets have magnetic fields and attract iron materials. However, electromagnets can be turned on and off by controlling the electric current, while bar magnets maintain their magnetism permanently. Additionally, electromagnets can be made stronger by increasing the number of wire coils or electric current, whereas the strength of bar magnets cannot be controlled.
Lecture 1 electromagnetism
Electromagnetism describes the interactions between electric and magnetic fields. Michael Faraday and James Clerk Maxwell first established that changing magnetic fields produce electric currents and changing electric fields produce magnetic fields. Maxwell showed that oscillating electric and magnetic fields propagate as electromagnetic waves, including radio waves, visible light, and others. All electromagnetic waves travel at the speed of light and have characteristics determined by their frequency or wavelength.
Reflex klystron amplifier , microwave klystron amplifier
The document discusses the reflex klystron, a single cavity microwave oscillator. It consists of an electron gun, a cavity with grids, and a repeller plate. Electrons emitted from the cathode are accelerated through the cavity, undergo velocity modulation, and are repelled back through the cavity. This produces electron bunching and microwave oscillations. Applications include radar receivers, local oscillators, signal sources, and parametric amplifiers.
Physics F 5: Electromagnet
The document discusses electromagnets and their magnetic field patterns. It defines an electromagnet as a magnetic field created by electric current through a coil. It describes how the magnetic field patterns of a straight wire, coil, and solenoid are determined using the right-hand grip rule. The strength of the magnetic field is affected by current, number of wire turns, and use of an iron core. Applications of electromagnets discussed include electric bells, relays, loudspeakers, and telephone earpieces.
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The document discusses the components and workings of an X-ray machine. It is comprised of a high voltage generator, X-ray tube, autotransformer, high voltage transformer, rectifier, tungsten filament, and operating console. X-rays are produced when high-speed electrons emitted from a filament collide with a metallic target in the X-ray tube. The electrons are accelerated using kilovolts peak (kVp) and milliamps (mA) which causes the electrons to lose kinetic energy upon impact, transforming it into X-ray radiation. Main components include the X-ray tube which houses the filament and target, as well as circuits to heat the filament and accelerate the electrons.
electrostatic Van de graaff generator
This kind of Van de Graaff generator is made up of:
• A motor
• Two rollers
• A belt
• Two brush assemblies
• An output terminal (usually a metal or aluminum sphere)
The strong negative charge from the roller now begins to do two things:
1. It repels the electrons near the tips of the lower brush assembly.
2. It begins to strip nearby air molecules of their electrons.
Applications:
1. It is used to generate x-rays, which is widely used in medicine field.
2. It is used in atom smasher’s, which is used in research purposes.
3. It found applications in physics, medicine, and astro physics.
Production of x rays
X-rays are produced when fast moving electrons are suddenly stopped upon impacting a metal target, converting their kinetic energy into X-rays (1%) and heat (>99%). An X-ray tube contains two electrodes sealed in a glass envelope: a cathode with a heated tungsten filament for thermionic emission of electrons, and an anode target of tungsten. Electrons bombard the target at nearly half the speed of light. Increasing the tube voltage or current independently increases the number and energy of X-rays produced via characteristic radiation lines and continuous Bremsstrahlung spectrum, shifting the spectrum to higher energies important for medical imaging.
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How electromagnets work
An electromagnet works by passing a current of electricity through a coil of wire wrapped around an iron core such as a nail. The electricity from a battery creates a magnetic force around the nail when the wire is connected, allowing it to attract magnetic materials. Turning off the current by disconnecting the wire causes the magnetic force to cease.
X ray production 2
X-rays are produced when high-speed electrons generated in a vacuum tube collide with a metal target, usually tungsten. This causes the electrons to lose energy, which is re-emitted from the target in the form of x-ray radiation. To prevent overheating, the target uses a rotating anode and circulating oil, with copper used for the anode mountings.
backward wave oscillator
An electron gun generates an electron beam that is interacting with a slow-wave structure.
It sustains the oscillations by propagating a traveling wave backwards against the beam
. The generated electromagnetic wave power has its group velocity directed oppositely to the direction of motion of the electrons.
The output power is coupled out near the electron gun.
Production of xray
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This document discusses superconductors, which are materials that exhibit zero electrical resistance below a critical temperature. Some key points made include:
- Superconductors include metals like aluminum, niobium, and magnesium diboride that show infinite conductivity below their critical temperature.
- Properties of superconductors include zero resistance, the Meissner effect of expelling magnetic fields, and a critical temperature/transition temperature below which they become superconducting.
- The Meissner effect was discovered in 1933 and causes superconductors to expel magnetic fields when cooled below their critical temperature.
- There are two main types of superconductors - type I, which lose superconductivity abruptly at
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Maxwell developed the unified theory of electromagnetism in 1873, which proposed that electric and magnetic fields are two aspects of the same phenomenon. He showed that electric and magnetic fields interact with each other and change over time. This theory predicted that electric and magnetic fields travel through space in the form of waves, which include radio waves. Radio waves have the longest wavelengths of all electromagnetic waves and their frequencies range from 300 GHz to 300 kHz. They were first produced in the late 1880s by Hertz using a spark-gap transmitter that generated radio pulses through a process called magnetic induction.
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How does an electromagnet work
Both bar magnets and electromagnets have magnetic fields and attract iron materials. However, electromagnets can be turned on and off by controlling the electric current, while bar magnets maintain their magnetism permanently. Additionally, electromagnets can be made stronger by increasing the number of wire coils or electric current, whereas the strength of bar magnets cannot be controlled.
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Electromagnetism describes the interactions between electric and magnetic fields. Michael Faraday and James Clerk Maxwell first established that changing magnetic fields produce electric currents and changing electric fields produce magnetic fields. Maxwell showed that oscillating electric and magnetic fields propagate as electromagnetic waves, including radio waves, visible light, and others. All electromagnetic waves travel at the speed of light and have characteristics determined by their frequency or wavelength.
Reflex klystron amplifier , microwave klystron amplifier
The document discusses the reflex klystron, a single cavity microwave oscillator. It consists of an electron gun, a cavity with grids, and a repeller plate. Electrons emitted from the cathode are accelerated through the cavity, undergo velocity modulation, and are repelled back through the cavity. This produces electron bunching and microwave oscillations. Applications include radar receivers, local oscillators, signal sources, and parametric amplifiers.
Physics F 5: Electromagnet
The document discusses electromagnets and their magnetic field patterns. It defines an electromagnet as a magnetic field created by electric current through a coil. It describes how the magnetic field patterns of a straight wire, coil, and solenoid are determined using the right-hand grip rule. The strength of the magnetic field is affected by current, number of wire turns, and use of an iron core. Applications of electromagnets discussed include electric bells, relays, loudspeakers, and telephone earpieces.
What is xray
The document discusses the components and workings of an X-ray machine. It is comprised of a high voltage generator, X-ray tube, autotransformer, high voltage transformer, rectifier, tungsten filament, and operating console. X-rays are produced when high-speed electrons emitted from a filament collide with a metallic target in the X-ray tube. The electrons are accelerated using kilovolts peak (kVp) and milliamps (mA) which causes the electrons to lose kinetic energy upon impact, transforming it into X-ray radiation. Main components include the X-ray tube which houses the filament and target, as well as circuits to heat the filament and accelerate the electrons.
electrostatic Van de graaff generator
This kind of Van de Graaff generator is made up of:
• A motor
• Two rollers
• A belt
• Two brush assemblies
• An output terminal (usually a metal or aluminum sphere)
The strong negative charge from the roller now begins to do two things:
1. It repels the electrons near the tips of the lower brush assembly.
2. It begins to strip nearby air molecules of their electrons.
Applications:
1. It is used to generate x-rays, which is widely used in medicine field.
2. It is used in atom smasher’s, which is used in research purposes.
3. It found applications in physics, medicine, and astro physics.
Production of x rays
X-rays are produced when fast moving electrons are suddenly stopped upon impacting a metal target, converting their kinetic energy into X-rays (1%) and heat (>99%). An X-ray tube contains two electrodes sealed in a glass envelope: a cathode with a heated tungsten filament for thermionic emission of electrons, and an anode target of tungsten. Electrons bombard the target at nearly half the speed of light. Increasing the tube voltage or current independently increases the number and energy of X-rays produced via characteristic radiation lines and continuous Bremsstrahlung spectrum, shifting the spectrum to higher energies important for medical imaging.
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A solar cell converts light into electricity via the photovoltaic effect. When light reaches the p-n junction of a semiconductor, electron-hole pairs are created which generate a voltage across the junction. The newly created electrons and holes are separated to the n-type and p-type sides respectively due to the junction's barrier potential, creating a small current flow if a load is connected. Common semiconductor materials used in solar cells include silicon, gallium arsenide, cadmium telluride, and copper indium selenide due to their band gaps close to 1.5 electronvolts.
Build an electromagnet
The document discusses how to build a simple electromagnet using copper wire wrapped around an iron nail, connected to a battery. When electric current flows through the wire, it creates a magnetic field that allows the nail to attract iron filings. The strength of an electromagnet depends on factors like the number of wire turns and amount of electric current. Electromagnets are found in many devices and have various applications because they can be switched on and off using electricity unlike permanent magnets.
Superconductors
This document provides an overview of superconductivity. It begins by defining superconductivity as the ability of certain materials to conduct electrical current with no resistance below a critical temperature. It distinguishes between Type I and Type II superconductors. It then describes the Meissner effect, where a superconductor in a magnetic field will expel the field. Applications of superconductivity discussed include magnetic levitation trains, medical imaging, power transmission, and particle accelerators. Charts show increasing critical temperatures over time and examples of superconducting power cables and maglev trains. Future applications proposed are solar power generation, wind turbines, and energy storage.
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This document discusses various topics related to electromagnetism including magnetic field lines, the direction of magnetic fields, electromagnets, Tesla coils, the electromagnetic spectrum, effects of ELF-EMF radiation on human cells, examples of electromagnetic radiation, and uses of electromagnetic waves. It provides introductions to key concepts and principles of electromagnetism.
Introduction to Radiology
There are three main sources of natural radiation: cosmic radiation from outer space, terrestrial radiation from the ground and building materials, and internal radiation from radioactive elements within the human body. Cosmic radiation consists of particles and gamma rays from the sun and beyond. Terrestrial radiation comes from elements like uranium and thorium in the Earth. Internal radiation originates from radioactive isotopes ingested or inhaled over a lifetime.
How electromagnets work
An electromagnet works by passing a current of electricity through a coil of wire wrapped around an iron core such as a nail. The electricity from a battery creates a magnetic force around the nail when the wire is connected, allowing it to attract magnetic materials. Turning off the current by disconnecting the wire causes the magnetic force to cease.
X ray production 2
X-rays are produced when high-speed electrons generated in a vacuum tube collide with a metal target, usually tungsten. This causes the electrons to lose energy, which is re-emitted from the target in the form of x-ray radiation. To prevent overheating, the target uses a rotating anode and circulating oil, with copper used for the anode mountings.
backward wave oscillator
An electron gun generates an electron beam that is interacting with a slow-wave structure.
It sustains the oscillations by propagating a traveling wave backwards against the beam
. The generated electromagnetic wave power has its group velocity directed oppositely to the direction of motion of the electrons.
The output power is coupled out near the electron gun.
Production of xray
This document summarizes the production of x-rays. It describes how x-rays are produced when electrons are accelerated toward a metal target in an x-ray tube. The tube contains a cathode that emits electrons and an anode, made of tungsten or similar high atomic number metal, that absorbs the electrons. When electrons strike the target, they cause two types of x-rays to be emitted - bremsstrahlung and characteristic x-rays. Bremsstrahlung x-rays are produced when electrons are deflected by the target's nuclei, while characteristic x-rays are emitted when electrons fill vacancies left by ejected inner shell electrons. The document also discusses components of the x-ray
Permanent Magnets and Electromagnets | Physics
Permanent Magnets: As the name suggests these are the type of magnets that can retain their magnetism for a considerate amount of time. They are usually made of hard materials which are strongly magnetized. Copy the link given below and paste it in new browser window to get more information on Permanent Magnets and Electromagnets www.askiitians.com/iit-jee-magnetism/permanent-magnets-and-electromagnets/
Quantum levitation
Superconductors expel magnetic fields below a critical temperature due to the Meissner effect. Quantum levitation occurs when a type-II superconductor is placed above a magnet. Magnetic flux tubes form and become pinned inside the superconductor, locking it in place against gravity. As the superconductor moves, energy increases due to the shifting flux tubes, creating a drag force that resists movement and provides stable levitation. Potential applications include frictionless trains and devices that could simulate weightlessness.
Band theory
Band theory describes how electrons are arranged in energy levels, or bands, within solid materials. There are generally three main bands - the conduction band, valence band, and forbidden gap. Insulators have a large forbidden gap, making it difficult for electrons to move between bands. Semiconductors have a smaller gap, allowing electrons to more easily move between bands with a small amount of energy. Conductors have no forbidden gap, allowing electrons to freely move between overlapping valence and conduction bands. The arrangement of bands determines whether a material is a conductor, insulator, or semiconductor, and how easily electrons can flow as electric current.
Superconductor
This document discusses superconductors, which are materials that exhibit zero electrical resistance below a critical temperature. Some key points made include:
- Superconductors include metals like aluminum, niobium, and magnesium diboride that show infinite conductivity below their critical temperature.
- Properties of superconductors include zero resistance, the Meissner effect of expelling magnetic fields, and a critical temperature/transition temperature below which they become superconducting.
- The Meissner effect was discovered in 1933 and causes superconductors to expel magnetic fields when cooled below their critical temperature.
- There are two main types of superconductors - type I, which lose superconductivity abruptly at
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The document proposes a rail breakage detector that uses electromagnetics to detect breaks or truncations in railway tracks. Electromagnetic waves would be generated and propagated laterally through the tracks. Any abrupt changes in amplitude, frequency, or wavelength of the waves detected by an oscilloscope in substations along the tracks every 100 km would indicate a break in the tracks between substations. This would allow breaks to be identified and accidents prevented by notifying the nearest station to the break. Implementing such a low-cost system could significantly improve railway safety in India given the number of recent accidents.
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Seema ppt
- 2. For Example :- Sound waves and Radio waves
- 3. Definition of electromagnetic wave. : one of the waves that are propagated by simultaneous periodic variations of electric and magnetic field intensity and that include radio waves, infrared, visible light, ultraviolet, X-rays, and gamma rays.
- 4. Activity for electromagnetic waves Take about 30cm of insulated copper wire. You can use the wire from an old transformer or motor. You can get it from mixer grinder repair shop Wind it around a iron nail or pencil stick. Pass current through the wire from a single pen torch cell or battery. A magnetic field is produced around the coil. From this activity you can conclude that magnetic field is found around a wire connecting electric current. Just like you create disturbance in water to produce waves, you can create disturbance in electric and magnetic field. Instead of direct current if alternating current is passed through the coil you can create disturbance in the electric field and magnetic field.
- 5. Properties of electromagnetic Waves :- • All the electromagnetic waves travel at the speed of light i.e. 3X10^8 m/s in vacuum. • They do not need any material medium for their propagation. • Electromagnetic waves are three dimensional transverse waves. • Electromagnetic waves have wide range of frequencies which react differently with matter.