5 min read•december 30, 2022
Saarah Hasan
Daniella Garcia-Loos
Saarah Hasan
Daniella Garcia-Loos
We briefly mentioned electromagnetic waves in 6.1, but let’s review them a little and get a bit more in-depth. Once again, what is an electromagnetic wave?
An electromagnetic wave is a wave that’s capable of transmitting its energy through a vacuum; electromagnetic waves are produced by the vibrations of charged particles, don’t require a medium to travel, and are always transverse.
Some new stuff to dig into: electromagnetic waves are made up of electric and magnetic fields that oscillate perpendicular to each other. As shown in the image below, both fields are perpendicular to each other and perpendicular to their direction of motion as well.
Another thing to remember: When electromagnetic waves travel through a vacuum, they all travel at a constant speed c, which equals 3*10^8m/s (the speed of light).
v=λ*f becomes c=λ*f
Here are some key things to know about electromagnetic waves:
There’s a broad spectrum of wavelengths and frequencies that electromagnetic waves cover, and electromagnetic waves can be categorized by these two characteristics. The entire range of waves is called the electromagnetic (EM) spectrum. Types of waves on the EM spectrum include:
The narrow band of wavelengths that the human eye can see is the visible light spectrum, whose colors in order of increasing wave frequency are red, orange, yellow, green, blue, and violet- remembered as ROYGBV. It’d be best to familiarize yourself with the names of the major categories of EM waves and ROYGBV.
Here are some key points about the electromagnetic spectrum:
Electromagnetic waves to the left of the spectrum—UV rays, X-rays, gamma rays—have high frequencies. Due to their high frequencies, these types of radiation have high energies, which can be detrimental to our health if precautions aren’t taken. That’s why we wear sunscreen whenever we go out and why lead shields are placed over parts of our body that aren’t being imaged whenever we get an X-ray.
Electromagnetic waves to the right of the spectrum—infrared rays, microwaves, radio waves—have low frequencies, so radiation from these types isn’t dangerous and doesn’t really affect our health.
Here are some key points about representations and models of electromagnetic waves:
1. In the electromagnetic spectrum, rank the following electromagnetic waves in terms of increasing wavelength.
2. For the five types of electromagnetic radiation listed above, which of the following correctly describes the way in which wavelength, frequency and speed, change as one goes from the left to right on the list?
Wavelength | Frequency | Speed | |
A | Decreases | Decreased | Decreases |
B | Decreases | Increased | Remains the Same |
C | Increases | Decreases | Remains the Same |
D | Increases | Decreases | Increases |
E | Increased | Increases | Increases |
Answers:
E: λ changes the opposite of frequencies (high freq = low λ) … based on this and knowledge of the EM spectrum, the answer is E.
B: Known facts about the EM spectrum.
Amplitude
: Amplitude refers to the maximum displacement or distance from equilibrium position that a particle in a wave moves. It represents the energy carried by the wave.Electric field
: An electric field refers to an invisible area surrounding an electrically charged object or particle, where other charged objects experience either attraction or repulsion forces.Electromagnetic wave
: An electromagnetic wave is a type of wave that consists of oscillating electric and magnetic fields, which travel through space at the speed of light.Frequency (f)
: Frequency refers to the number of complete cycles or oscillations per unit time. In physics, it specifically refers to the number of wave crests passing through a given point per second.Gamma rays
: Gamma rays are high-energy electromagnetic waves that are emitted from the nucleus of an atom during radioactive decay.Infrared radiation
: Infrared radiation refers to electromagnetic waves with longer wavelengths than those of visible light but shorter than microwaves. It is associated with heat energy and is often used in devices like remote controls and thermal cameras.Magnetic field
: A magnetic field is a region in space where a magnetic force can be detected. It is created by moving electric charges or by magnets.Microwaves
: Microwaves are a type of electromagnetic radiation with longer wavelengths than those of visible light. They are commonly used in microwave ovens to heat food.ROYGBV
: ROYGBV is an acronym that represents the colors of the visible light spectrum in order: Red, Orange, Yellow, Green, Blue, and Violet.Sine Wave
: A sine wave is a smooth repetitive oscillation that can be represented by a mathematical function called sine. It has a characteristic shape resembling gentle hills and valleys.Speed of light (c)
: The speed of light is the fastest possible speed at which energy or information can travel in a vacuum. It is approximately 299,792,458 meters per second.Transverse wave
: A transverse wave is a type of wave in which particles vibrate perpendicular to the direction in which the wave travels.Ultraviolet radiation
: Ultraviolet radiation refers to a type of electromagnetic radiation that has a shorter wavelength and higher energy than visible light. It is commonly found in sunlight and can cause sunburns and skin damage.Visible light
: Visible light is the portion of the electromagnetic spectrum that can be detected by the human eye. It consists of different colors with varying wavelengths, ranging from red to violet.Wavelength (λ)
: Wavelength refers to the distance between two consecutive points on a wave that are in phase with each other. It is usually measured from crest to crest or trough to trough.X-rays
: X-rays are a form of high-energy electromagnetic waves that have shorter wavelengths than ultraviolet rays but longer wavelengths than gamma rays. They are commonly used in medical imaging to visualize bones and internal structures.5 min read•december 30, 2022
Saarah Hasan
Daniella Garcia-Loos
Saarah Hasan
Daniella Garcia-Loos
We briefly mentioned electromagnetic waves in 6.1, but let’s review them a little and get a bit more in-depth. Once again, what is an electromagnetic wave?
An electromagnetic wave is a wave that’s capable of transmitting its energy through a vacuum; electromagnetic waves are produced by the vibrations of charged particles, don’t require a medium to travel, and are always transverse.
Some new stuff to dig into: electromagnetic waves are made up of electric and magnetic fields that oscillate perpendicular to each other. As shown in the image below, both fields are perpendicular to each other and perpendicular to their direction of motion as well.
Another thing to remember: When electromagnetic waves travel through a vacuum, they all travel at a constant speed c, which equals 3*10^8m/s (the speed of light).
v=λ*f becomes c=λ*f
Here are some key things to know about electromagnetic waves:
There’s a broad spectrum of wavelengths and frequencies that electromagnetic waves cover, and electromagnetic waves can be categorized by these two characteristics. The entire range of waves is called the electromagnetic (EM) spectrum. Types of waves on the EM spectrum include:
The narrow band of wavelengths that the human eye can see is the visible light spectrum, whose colors in order of increasing wave frequency are red, orange, yellow, green, blue, and violet- remembered as ROYGBV. It’d be best to familiarize yourself with the names of the major categories of EM waves and ROYGBV.
Here are some key points about the electromagnetic spectrum:
Electromagnetic waves to the left of the spectrum—UV rays, X-rays, gamma rays—have high frequencies. Due to their high frequencies, these types of radiation have high energies, which can be detrimental to our health if precautions aren’t taken. That’s why we wear sunscreen whenever we go out and why lead shields are placed over parts of our body that aren’t being imaged whenever we get an X-ray.
Electromagnetic waves to the right of the spectrum—infrared rays, microwaves, radio waves—have low frequencies, so radiation from these types isn’t dangerous and doesn’t really affect our health.
Here are some key points about representations and models of electromagnetic waves:
1. In the electromagnetic spectrum, rank the following electromagnetic waves in terms of increasing wavelength.
2. For the five types of electromagnetic radiation listed above, which of the following correctly describes the way in which wavelength, frequency and speed, change as one goes from the left to right on the list?
Wavelength | Frequency | Speed | |
A | Decreases | Decreased | Decreases |
B | Decreases | Increased | Remains the Same |
C | Increases | Decreases | Remains the Same |
D | Increases | Decreases | Increases |
E | Increased | Increases | Increases |
Answers:
E: λ changes the opposite of frequencies (high freq = low λ) … based on this and knowledge of the EM spectrum, the answer is E.
B: Known facts about the EM spectrum.
Amplitude
: Amplitude refers to the maximum displacement or distance from equilibrium position that a particle in a wave moves. It represents the energy carried by the wave.Electric field
: An electric field refers to an invisible area surrounding an electrically charged object or particle, where other charged objects experience either attraction or repulsion forces.Electromagnetic wave
: An electromagnetic wave is a type of wave that consists of oscillating electric and magnetic fields, which travel through space at the speed of light.Frequency (f)
: Frequency refers to the number of complete cycles or oscillations per unit time. In physics, it specifically refers to the number of wave crests passing through a given point per second.Gamma rays
: Gamma rays are high-energy electromagnetic waves that are emitted from the nucleus of an atom during radioactive decay.Infrared radiation
: Infrared radiation refers to electromagnetic waves with longer wavelengths than those of visible light but shorter than microwaves. It is associated with heat energy and is often used in devices like remote controls and thermal cameras.Magnetic field
: A magnetic field is a region in space where a magnetic force can be detected. It is created by moving electric charges or by magnets.Microwaves
: Microwaves are a type of electromagnetic radiation with longer wavelengths than those of visible light. They are commonly used in microwave ovens to heat food.ROYGBV
: ROYGBV is an acronym that represents the colors of the visible light spectrum in order: Red, Orange, Yellow, Green, Blue, and Violet.Sine Wave
: A sine wave is a smooth repetitive oscillation that can be represented by a mathematical function called sine. It has a characteristic shape resembling gentle hills and valleys.Speed of light (c)
: The speed of light is the fastest possible speed at which energy or information can travel in a vacuum. It is approximately 299,792,458 meters per second.Transverse wave
: A transverse wave is a type of wave in which particles vibrate perpendicular to the direction in which the wave travels.Ultraviolet radiation
: Ultraviolet radiation refers to a type of electromagnetic radiation that has a shorter wavelength and higher energy than visible light. It is commonly found in sunlight and can cause sunburns and skin damage.Visible light
: Visible light is the portion of the electromagnetic spectrum that can be detected by the human eye. It consists of different colors with varying wavelengths, ranging from red to violet.Wavelength (λ)
: Wavelength refers to the distance between two consecutive points on a wave that are in phase with each other. It is usually measured from crest to crest or trough to trough.X-rays
: X-rays are a form of high-energy electromagnetic waves that have shorter wavelengths than ultraviolet rays but longer wavelengths than gamma rays. They are commonly used in medical imaging to visualize bones and internal structures.© 2024 Fiveable Inc. All rights reserved.
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