Chapter 13 - The Electromagnetic Spectrum Flashcards
What type of wave are the waves in the electromagnetic spectrum?
Transverse
Electromagnetic waves definition
They are electric and magnetic disturbances that transfer energy (NOT MATTER)
Name the order of the electromagnetic spectrum starting from the lowest wavelength
Radio
Microwave
Infrared
Visible
Ultraviolet
X-ray
Gamma ray
Red Meat Is Very Useful Xcept Goats
What wavelengths can the human eye see between?
350 nm and 650 nm
All electromagnetic waves travel at ___________ in a vacuum
All electromagnetic waves travel at 3x10^8 m/s in a vacuum
What is the equation linking wave speed, frequency and wavelength?
Wave speed = Frequency x Wavelength
When you combine all the colours of the spectrum you get the colour __________
white
Violet has the ________ wavelength and red with the ____________ wavelength
shortest, longest
Uses of light (4 uses)
Torches
Cameras
Endoscopes
Optical fibres
True or false? All objects emit infrared radiation
True
Uses of infrared radiation (4 uses, think of red light!)
Optical fibres
Remote controls
Thermal imaging
Ovens
Uses of microwaves (3 uses)
Microwave oven
Mobile phones
Satellite communication
Uses of radio waves (3 uses)
Radio
Bluetooth
Remote Control Car
Dangers of infrared (2 dangers)
Skin burns
Damage to eyesight
Dangers of microwaves and radio waves
Heating internal body parts
Waves can transfer _______ and __________
energy, information
Carrier waves are waves that carry ____________. They do this by ______________________________
information, varying their amplitude
EM waves change properties based on their __________ and ___________________
frequency, wavelength
Shorter _________ (higher ________) mean more waves can arrive at the same time so more info can be transferred
wavelengths, frequency
Downside to shorter wavelengths carrying information
Their range is less, due to increased absorption by the atmosphere (which means they spread out less)
Radio waves have uses depending on their _________
wavelength
What device converts sound to an electrical signal?
A microphone
Are the brains of children or adults affected by mobile phone use?
-> Mobile phones use microwave signals
-> Children have thinner skulls than adults
-> Their brains may be more affected by mobile phone radiation
Which 2 parts of the EM spectrum do optical fibres use?
-> transparent fibres that are used to transmit signals by IR and visible light
-> these can transfer more information because light has a shorter wavelength than radio waves
-> more secure because signal is contained in fibre not in air
Uses of UV (think of escape rooms)
Security:
banknotes (uv markings)
security pens
Dangers of UV (3 dangers)
- Sunburn (which can lead to premature aging of the skin)
- Increases chance of skin cancer
- Can cause damage to eyes (potentially blindness
Gamma rays uses (2 uses)
- Killing harmful bacteria in food or on surgical equipment
- Cancer treatment
Use of x-rays
Medical imaging
What is ionisation?
What is its cause?
What happens if ionisation happens to living cells?
- When an atom gains or loses an electron
- Cause = x rays or gamma rays passing through a substance
- If ionisation happens to living cells it can damage cells and potentially cause cancer
What do people who work with ionising radiation wear?
A safety film badge
