What is electromagnetic wave

The way this is drawn, with B up and E toward us would represent a wave direction going to the left, not to the right. The right hand rule is such that if your fingers are along E and they curl in the direction of B (same as the direction your palm faces) then your thumb sticking out perpendicular points in the direction of the electromagnetic wave, so in your example you'd need to switch the B and E fields drawn to have a wave going to the right. Ink and paint absorb light of certain wavelengths and reflect others. These are subtractive colors. When you only mix a few colors, the combination will only reflect colors that all of the original ones reflect. That is why you get black or dark brown when you mix a bunch of paints together. Pixels, on the other hand, emit light, rather than reflect it. These are additive colors. For most computers and TVs, there are red, blue, and two green LEDs in pixels, but some fancy screens also have yellow. There are two greens because our eyes are most sensitive to green, around 550 nm wavelength. When you want white light, all of the LEDs light up; when you want black, all are dim. For any color in between, the screen lights up the appropriate LEDs the appropriate amounts to get the mix of these colors to be the color you want. Hello Jacob, Radio is old! The technology and vocabulary grew up over the last century. You are correct "micro: is not μ or 10^-6. Rather, it is a relative comparison of the waveform size to the traditional freque...

https://phys.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fphys.libretexts.org%2FBookshelves%2FUniversity_Physics%2FBook%253A_University_Physics_(OpenStax)%2FBook%253A_University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)%2F16%253A_Electromagnetic_Waves%2F16.02%253A_Maxwells_Equations_and_Electromagnetic_Waves Expand/collapse global hierarchy • Home • Bookshelves • University Physics • Book: University Physics (OpenStax) • University Physics II - Thermodynamics, Electricity, and Magnetism (OpenStax) • 16: Electromagnetic Waves • 16.2: Maxwell’s Equations and Electromagnetic Waves Expand/collapse global location \( \newcommand\) • • • • • • • • • Learning Objectives By the end of this section, you will be able to: • Explain Maxwell’s correction of Ampère’s law by including the displacement current • State and apply Maxwell’s equations in integral form • Describe how the symmetry between changing electric and changing magnetic fields explains Maxwell’s prediction of electromagnetic waves • Describe how Hertz confirmed Maxwell’s prediction of electromagnetic waves James Clerk Maxwell (1831–1879) was one of the major contributors to physics in the nineteenth century (Figure \(\PageIndex\): James Clerk Maxwell, a nineteenth-century physicist, developed a theory that explained the relationship between electricity and magnetism, and correctly predicted that visible light consists of electromagnetic waves. Maxwell’s Correction to the Laws of Electri...

\( \newcommand\) • The topic of this book is applied engineering electromagnetics. This topic is often described as “the theory of electromagnetic fields and waves,” which is both true and misleading. The truth is that electric fields, magnetic fields, their sources, waves, and the behavior these waves are all topics covered by this book. The misleading part is that our principal aim shall be to close the gap between basic electrical circuit theory and the more general theory that is required to address certain topics that are of broad and common interest in the field of electrical engineering. (For a preview of topics where these techniques are required, see the list at the end of this section.) In basic electrical circuit theory, the behavior of devices and systems is abstracted in such a way that the underlying electromagnetic principles do not need to be considered. Every student of electrical engineering encounters this, and is grateful since this greatly simplifies analysis and design. For example, a resistor is commonly defined as a device which exhibits a particular voltage \[V = IR \nonumber \] in response to a current \(I\), and the resistor is therefore completely described by the value \(R\). This is an example of a “lumped element” abstraction of an electrical device. Much can be accomplished knowing nothing else about resistors; no particular knowledge of the physical concepts of electrical potential, conduction current, or resistance is required. However, th...

[ "article:topic", "Electromagnetic waves", "authorname:openstax", "Electric field", "Magnetic Field", "amplitude", "transverse wave", "wavelength", "frequency", "Magnetic field strength", "Electric field strength", "standing wave", "resonant", "oscillate", "license:ccby", "showtoc:no", "program:openstax", "licenseversion:40", "source@https://openstax.org/details/books/college-physics" ] \( \newcommand\) • • • • • Learning Objectives By the end of this section, you will be able to: • Describe the electric and magnetic waves as they move out from a source, such as an AC generator. • Explain the mathematical relationship between the magnetic field strength and the electrical field strength. • Calculate the maximum strength of the magnetic field in an electromagnetic wave, given the maximum electric field strength. We can get a good understanding of electromagnetic waves (EM) by considering how they are produced. Whenever a current varies, associated electric and magnetic fields vary, moving out from the source like waves. Perhaps the easiest situation to visualize is a varying current in a long straight wire, produced by an AC generator at its center, as illustrated in Figure \(\PageIndex\) reveals the periodic nature of the generator-driven charges oscillating up and down in the antenna and the electric field produced. At time \(t = 0\), there is the maximum separation of charge, with negative charges at the top and positive charges at the bottom, producing the maximum magn...

• Afrikaans • አማርኛ • Anarâškielâ • العربية • Aragonés • অসমীয়া • Asturianu • Azərbaycanca • تۆرکجه • বাংলা • Bân-lâm-gú • Башҡортса • Беларуская • Беларуская (тарашкевіца) • Български • Bosanski • Català • Чӑвашла • Čeština • Cymraeg • Dansk • Deutsch • Eesti • Ελληνικά • Español • Esperanto • Euskara • فارسی • Fiji Hindi • Français • Gaeilge • Galego • 한국어 • Հայերեն • हिन्दी • Hrvatski • Bahasa Indonesia • Interlingua • Interlingue • IsiZulu • Íslenska • Italiano • עברית • Jawa • ქართული • Kiswahili • Kreyòl ayisyen • Kriyòl gwiyannen • Кыргызча • Latina • Latviešu • Lietuvių • Limburgs • Magyar • Македонски • Malagasy • മലയാളം • Bahasa Melayu • Mirandés • Монгол • မြန်မာဘာသာ • Nederlands • नेपाली • नेपाल भाषा • 日本語 • Nordfriisk • Norsk bokmål • Norsk nynorsk • Occitan • Oromoo • Oʻzbekcha / ўзбекча • ਪੰਜਾਬੀ • پنجابی • پښتو • Patois • Polski • Português • Română • Русиньскый • Русский • Scots • Seeltersk • Shqip • Simple English • Slovenčina • Slovenščina • کوردی • Српски / srpski • Srpskohrvatski / српскохрватски • Sunda • Suomi • Svenska • Tagalog • தமிழ் • ไทย • Türkçe • Тыва дыл • Українська • اردو • ئۇيغۇرچە / Uyghurche • Tiếng Việt • Võro • Winaray • 吴语 • ייִדיש • 粵語 • 中文 In electromagnetic radiation ( EMR) consists of electromagnetic waves, which are synchronized c. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a Electromagnetic waves ar...

https://phys.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fphys.libretexts.org%2FBookshelves%2FUniversity_Physics%2FBook%253A_University_Physics_(OpenStax)%2FBook%253A_University_Physics_II_-_Thermodynamics_Electricity_and_Magnetism_(OpenStax)%2F16%253A_Electromagnetic_Waves%2F16.02%253A_Maxwells_Equations_and_Electromagnetic_Waves Expand/collapse global hierarchy • Home • Bookshelves • University Physics • Book: University Physics (OpenStax) • University Physics II - Thermodynamics, Electricity, and Magnetism (OpenStax) • 16: Electromagnetic Waves • 16.2: Maxwell’s Equations and Electromagnetic Waves Expand/collapse global location \( \newcommand\) • • • • • • • • • Learning Objectives By the end of this section, you will be able to: • Explain Maxwell’s correction of Ampère’s law by including the displacement current • State and apply Maxwell’s equations in integral form • Describe how the symmetry between changing electric and changing magnetic fields explains Maxwell’s prediction of electromagnetic waves • Describe how Hertz confirmed Maxwell’s prediction of electromagnetic waves James Clerk Maxwell (1831–1879) was one of the major contributors to physics in the nineteenth century (Figure \(\PageIndex\): James Clerk Maxwell, a nineteenth-century physicist, developed a theory that explained the relationship between electricity and magnetism, and correctly predicted that visible light consists of electromagnetic waves. Maxwell’s Correction to the Laws of Electri...

\( \newcommand\) • The topic of this book is applied engineering electromagnetics. This topic is often described as “the theory of electromagnetic fields and waves,” which is both true and misleading. The truth is that electric fields, magnetic fields, their sources, waves, and the behavior these waves are all topics covered by this book. The misleading part is that our principal aim shall be to close the gap between basic electrical circuit theory and the more general theory that is required to address certain topics that are of broad and common interest in the field of electrical engineering. (For a preview of topics where these techniques are required, see the list at the end of this section.) In basic electrical circuit theory, the behavior of devices and systems is abstracted in such a way that the underlying electromagnetic principles do not need to be considered. Every student of electrical engineering encounters this, and is grateful since this greatly simplifies analysis and design. For example, a resistor is commonly defined as a device which exhibits a particular voltage \[V = IR \nonumber \] in response to a current \(I\), and the resistor is therefore completely described by the value \(R\). This is an example of a “lumped element” abstraction of an electrical device. Much can be accomplished knowing nothing else about resistors; no particular knowledge of the physical concepts of electrical potential, conduction current, or resistance is required. However, t...

[ "article:topic", "Electromagnetic waves", "authorname:openstax", "Electric field", "Magnetic Field", "amplitude", "transverse wave", "wavelength", "frequency", "Magnetic field strength", "Electric field strength", "standing wave", "resonant", "oscillate", "license:ccby", "showtoc:no", "program:openstax", "licenseversion:40", "source@https://openstax.org/details/books/college-physics" ] \( \newcommand\) • • • • • Learning Objectives By the end of this section, you will be able to: • Describe the electric and magnetic waves as they move out from a source, such as an AC generator. • Explain the mathematical relationship between the magnetic field strength and the electrical field strength. • Calculate the maximum strength of the magnetic field in an electromagnetic wave, given the maximum electric field strength. We can get a good understanding of electromagnetic waves (EM) by considering how they are produced. Whenever a current varies, associated electric and magnetic fields vary, moving out from the source like waves. Perhaps the easiest situation to visualize is a varying current in a long straight wire, produced by an AC generator at its center, as illustrated in Figure \(\PageIndex\) reveals the periodic nature of the generator-driven charges oscillating up and down in the antenna and the electric field produced. At time \(t = 0\), there is the maximum separation of charge, with negative charges at the top and positive charges at the bottom, producing the maximum magn...

The way this is drawn, with B up and E toward us would represent a wave direction going to the left, not to the right. The right hand rule is such that if your fingers are along E and they curl in the direction of B (same as the direction your palm faces) then your thumb sticking out perpendicular points in the direction of the electromagnetic wave, so in your example you'd need to switch the B and E fields drawn to have a wave going to the right. Ink and paint absorb light of certain wavelengths and reflect others. These are subtractive colors. When you only mix a few colors, the combination will only reflect colors that all of the original ones reflect. That is why you get black or dark brown when you mix a bunch of paints together. Pixels, on the other hand, emit light, rather than reflect it. These are additive colors. For most computers and TVs, there are red, blue, and two green LEDs in pixels, but some fancy screens also have yellow. There are two greens because our eyes are most sensitive to green, around 550 nm wavelength. When you want white light, all of the LEDs light up; when you want black, all are dim. For any color in between, the screen lights up the appropriate LEDs the appropriate amounts to get the mix of these colors to be the color you want. Hello Jacob, Radio is old! The technology and vocabulary grew up over the last century. You are correct "micro: is not μ or 10^-6. Rather, it is a relative comparison of the waveform size to the traditional freque...

• Afrikaans • አማርኛ • Anarâškielâ • العربية • Aragonés • অসমীয়া • Asturianu • Azərbaycanca • تۆرکجه • বাংলা • Bân-lâm-gú • Башҡортса • Беларуская • Беларуская (тарашкевіца) • Български • Bosanski • Català • Чӑвашла • Čeština • Cymraeg • Dansk • Deutsch • Eesti • Ελληνικά • Español • Esperanto • Euskara • فارسی • Fiji Hindi • Français • Gaeilge • Galego • 한국어 • Հայերեն • हिन्दी • Hrvatski • Bahasa Indonesia • Interlingua • Interlingue • IsiZulu • Íslenska • Italiano • עברית • Jawa • ქართული • Kiswahili • Kreyòl ayisyen • Kriyòl gwiyannen • Кыргызча • Latina • Latviešu • Lietuvių • Limburgs • Magyar • Македонски • Malagasy • മലയാളം • Bahasa Melayu • Mirandés • Монгол • မြန်မာဘာသာ • Nederlands • नेपाली • नेपाल भाषा • 日本語 • Nordfriisk • Norsk bokmål • Norsk nynorsk • Occitan • Oromoo • Oʻzbekcha / ўзбекча • ਪੰਜਾਬੀ • پنجابی • پښتو • Patois • Polski • Português • Română • Русиньскый • Русский • Scots • Seeltersk • Shqip • Simple English • Slovenčina • Slovenščina • کوردی • Српски / srpski • Srpskohrvatski / српскохрватски • Sunda • Suomi • Svenska • Tagalog • தமிழ் • ไทย • Türkçe • Тыва дыл • Українська • اردو • ئۇيغۇرچە / Uyghurche • Tiếng Việt • Võro • Winaray • 吴语 • ייִדיש • 粵語 • 中文 In electromagnetic radiation ( EMR) consists of electromagnetic waves, which are synchronized c. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a Electromagnetic waves ar...