Waves - Diffraction and EM spectrum Flashcards
Which wave on the EM spectrum has the longest wavelength?
Radio waves
Which wave on the EM spectrum has the shortest wavelength?
Gamma rays
If a wave has a high frequency what does that tell us about the wavelength?
It has a short wavelength
If a wave has a low frequency what does that tell us about the wavelength?
It has a long wavelength
Smaller wavelengths diffract (more/less) around objects.
They diffract less.
This is why houses in valleys cannot receive TV signals.
Longer wavelengths diffract (more/less) around objects.
They diffract more.
This is why houses in valleys can receive radio signals but cannot receive TV signals.
What is used to detect Radio waves?
Antenna
What is used to detect microwaves?
Antenna
CCD
What is used to detect infrared light?
Blackened thermometer
Photodiode
Phototransistor
Thermistor
LDR
Thermocouple
What is used to detect visible light?
Photodiode
Phototransistor
Thermistor
LDR
Photographic film
What is used to detect ultraviolet light?
Photodiode
Phototransistor
LDR
Fluorescent materials
What is used to detect x-rays?
Photographic film
Photodiode
Phototransistor
CCD
What is used to detect gamma rays?
Photodiode
Geiger-Muller tube
What are radio waves used for?
Radio and TV signals
What are microwaves used for?
Mobile phone signals
Heating up food
What is infrared light used for?
Thermal Imaging camera
Remote controls
What is visible light used for?
Allows us to see
Lightbulbs
Lasers
What is ultraviolet light used for?
Detecting counterfeit bank notes
Setting dental fillings
Sterilising medical instruments
What are x-rays used for?
Airport security
Medical examinations
Non-destructive testing
What are gamma rays used for?
Medical tracers
Killing cells
What is diffraction?
The bending of waves around an object.
