Electromagnetic Spectrum (Cambridge (CIE) IGCSE Physics)
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True or False?
The electromagnetic spectrum is arranged in a specific order based on the wavelengths or frequencies.
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Cards in this collection (42)
True or False?
The electromagnetic spectrum is arranged in a specific order based on the wavelengths or frequencies.
True.
The electromagnetic spectrum is arranged in a specific order based on the wavelengths or frequencies.
What is the order of the electromagnetic spectrum from longest to shortest wavelength?
The order of the electromagnetic spectrum from longest to shortest wavelength is:
Radio waves
Microwaves
Infrared
Visible light
Ultraviolet
X-rays
Gamma rays
What are the properties of electromagnetic waves?
All electromagnetic waves share the following properties:
transverse
can through a vacuum
travel at the same speed in a vacuum
form a continuous spectrum
Define the term electromagnetic waves.
Electromagnetic waves are transverse waves with oscillating electric and magnetic fields that transfer energy from the source of the waves to an absorber.
True or False?
The speed of electromagnetic waves in air is the same as in a vacuum. (Extended Tier Only)
True.
The speed of electromagnetic waves in air can be approximated to the speed of light in a vacuum because the difference in speed is so small.
What is the relationship between the frequency of electromagnetic waves and the energy they transfer?
The higher the frequency, the higher the energy of the radiation, and vice versa.
What is a mnemonic for remembering the order of radiation types in the electromagnetic spectrum?
One possible mnemonic for remembering the electromagnetic spectrum is:
Raging Martians Invaded Venus Using X-ray Guns.
Identify using the diagram the electromagnetic radiation type with the shortest wavelength.
The electromagnetic radiation type with the shortest wavelength is gamma rays.
Identify using the diagram the electromagnetic radiation type with the highest frequency.
The electromagnetic radiation type with the highest frequency is gamma rays.
Define the term fluorescence.
Fluorescence is the process where certain substances absorb ultraviolet light and re-emit it as visible light, causing them to glow.
What is the main application of radio waves?
The main application of radio waves is in wireless communications.
What are the two main applications of microwaves?
The two main applications of microwaves are:
heating food
wireless communications
True or False?
Night vision cameras use infrared radiation.
True.
One application of infrared radiation is night vision cameras.
True or False?
Gamma radiation is used in fibre optic communications.
False.
Infrared and visible light are used in optic fibre communications. Gamma rays are used for sterilising medical equipment and treating cancer.
True or False?
Sterilising water and detecting fake bank notes are two applications of X-rays.
False.
Sterilising water and detecting fake bank notes are two applications of ultraviolet radiation (UV). X-rays are used for imaging in medicine, dentistry, airport security and industry.
True or False?
Visible light is the only part of the electromagnetic spectrum that human eyes can see.
True.
Human eyes can only detect wavelengths of electromagnetic radiation in the visible light section of the electromagnetic spectrum.
True or False?
Remote controls are one application of ultraviolet radiation.
False.
Ultraviolet radiation carries too much energy and would be harmful if used for this purpose. Remote controls are one application of infrared radiation.
State the type of radiation used in the device in the diagram.
The device in the diagram is a microwave oven and uses microwaves.
True or False?
As the frequency of electromagnetic waves increases, so does the energy and the danger associated with them.
True.
As the frequency of electromagnetic waves increases, the energy they transfer increases, and therefore so does the danger associated with them.
What is the main danger associated with ultraviolet, X-rays, and gamma rays?
Ultraviolet, X-rays, and gamma rays can all ionise atoms, which can damage cells and cause mutations, which can lead to cancer.
True or False?
Radio waves are known to be harmful to humans.
False.
There are no known harmful effects of radio waves.
True or False?
Microwaves can be harmful to humans.
True.
Microwaves can be harmful to humans in high levels of exposure, because higher-frequency microwaves cause internal heating.
True or False?
Mobile phones emit microwave radiation.
True.
Mobile phones do emit microwave radiation, but only at low energies which are not known to cause any harm.
True or False?
Ultraviolet radiation can be harmful to humans.
True.
Ultraviolet radiation can cause sunburn, eye damage and skin cancer.
True or False?
X-rays and gamma rays can be harmful to humans.
True.
X-rays and gamma rays (and UV) are ionising radiation which can remove electrons from atoms, causing damage to DNA which can lead to cell and tissue damage, mutations and cancer.
True or False?
Sunscreen absorbs ultraviolet light, preventing it from damaging the skin.
True.
Sunscreen absorbs ultraviolet light, preventing it from damaging the skin.
True or False?
Ionising forms of electromagnetic radiation have a higher frequency than visible light.
True.
The ionising forms of electromagnetic radiation are ultraviolet, X-rays and gamma rays, all of which have higher frequencies than visible light.
True or False?
The longer the wavelength, the more ionising the electromagnetic radiation.
False.
The shorter the wavelength (and therefore, the higher the frequency), the more ionising the electromagnetic radiation.
State the purpose of the device in the image.
The device in the image is a radiation badge and its purpose is to measure a person's exposure to radiation.
What is a geostationary satellite?
A geostationary satellite is a satellite that orbits above the Earth's equator.
What is the orbital period of a geostationary satellite?
The orbital period of a geostationary satellite is 24 hours.
True or False?
Polar satellites orbit higher above the Earth's surface than geostationary satellites.
False.
Geostationary satellites orbit much higher above the Earth's surface than polar satellites do.
What are geostationary satellites used for?
The high orbit of geostationary satellites makes them useful for radio and telecommunications broadcasting around the world.
What is a polar satellite?
A polar satellite is a satellite that orbits around the Earth's north and south poles.
True or False?
Polar satellites are also known as low-orbit satellites.
True.
Polar satellites are also known as low-orbit satellites because they orbit much closer to the Earth's surface than geostationary satellites.
What are polar satellites used for?
Polar satellites are used for:
monitoring the weather
military applications
taking images of the Earth's surface
Why are polar satellites used for military applications rather than geostationary satellites?
Polar satellites have a lower orbit, therefore there is a much shorter time delay between sending and receiving signals, and the images are much clearer. This makes polar satellites more suitable for certain applications including military use.
Why are microwaves used for wireless internet? (Extended Tier Only)
Microwaves are used for wireless internet (WiFi) because microwaves can penetrate some walls and only require a short ariel for transmission and reception.
Why are radio waves used for Bluetooth? (Extended Tier Only)
Radio waves can pass through walls but the signal is weakened by doing so, therefore radio waves are useful for very short-range communications such as Bluetooth.
True or False?
The value of an analogue signal can vary continuously. (Extended Tier Only)
True.
The value of analogue signals can vary continuously. They can take any value.
What type of signal can only take one of two discrete states? (Extended Tier Only)
Digital signals can only take discrete states such as:
1 and 0
high and low
on and off
True or False?
One advantage of a digital signal over an analogue signal is that a digital signal can be regenerated so there is minimal noise. (Extended Tier Only)
True.
A digital signal can be regenerated (restored to its original characteristics) so there is minimal noise (unwanted disturbance in the signal). This increases the range of the signal so it can be transmitted over larger distances.
