Radiation (EM Spectrum) Flashcards
Give one use of ultraviolet.
- security marking
- detecting forged bank notes
- fluorescent lamps
Which wave in the electromagnetic spectrum has the longest wavelength?
Radio waves have the longest wavelength.
In what way is UV (ultraviolet) a danger?
Too much exposure to UV can cause skin cancer.
Give one application of microwaves.
- heating food
- mobile phone communications
How does UV (ultraviolet) benefit human health?
UV helps generate vitamin D for healthy skin.
What do all waves in the electromagnetic spectrum have in common?
All waves in the electromagnetic spectrum travel at the same speed (the speed of light).
Give one use of infrared.
- thermal imaging
- remote controls
- security systems (motion sensor)
Which wave in the electromagnetic spectrum has the least energy?
Radio waves have the least energy.
Give one use of X-rays.
- medical X-ray scans
- airport security scanners
State a detector of infrared radiation.
- photodiode
- phototransistor
- thermistor
- thermocouple
Give one application of radio waves.
- Broadcasting
- Satellite transmissions
- Communications
What speed do all waves in the electromagnetic spectrum travel at?
All waves in the electromagnetic spectrum travel at the speed of light - 3 x 108 ms-1.
Which wave in the electromagnetic spectrum has the shortest wavelength?
Gamma rays have the shortest wavelength.
How is the frequency of a wave in the e.m. spectrum related to its energy?
The higher the frequency of a wave in the e.m. spectrum, the more energy the wave has.
State a detector of UV (ultraviolet).
Fluorescent material can be used to detect UV.
This can be in the form of special ink, or chemicals in washing powder.
Give one application of gamma rays.
- sterilising food and medical equipment
- treating cancer
- medical tracers
State a detector of radio waves.
An aerial is used to detect radio waves.
Name the seven different types of waves in the electromagnetic spectrum.
Try to list them from long λ (wavelength) to short λ.
Radio (long λ)
Microwaves
Infrared
Visible
Ultraviolet
X-rays
Gamma rays (short λ)
Give one use of visible light.
- photography
- illumination
- car headlights
- street lighting
- barcode scanner at checkout
What type of radiation does a laser emit?
A laser will emit one single frequency (and wavelength) of ‘light’. Normally this is visible light (e.g. red, green, blue) but it possible to get infrared lasers.
Which wave in the electromagnetic spectrum has the greatest energy?
Gamma rays have the greatest energy.
Complete the following sentence:
All waves carry ……………
All waves carry energy.
Describe what is meant by gamma radiation.
- Gamma radiation is a wave in the electromagnetic spectrum
- Gamma rays have no mass or charge
- Gamma rays have a very short wavelength and a high frequency
Explain how an X-ray image is produced.
X-rays are directed towards an object (e.g. suspected broken bone, metal weld).
X-rays are absorbed by dense material such as bone. This shows up as white on photographic film.
X-rays will pass through gaps or low-density material. This will show up as black on photographic film.
Explain how UV (ultraviolet) is used to check security markings (e.g. on banknotes).
The UV causes special chemicals (fluorescent material) to glow / give off visible light.
Which material(s) can X-rays pass through?
1. Metal
2. Bone
3. Skin
X-rays can pass through C. skin.
(Bone is too dense for X-rays to fully pass through, and metal will reflect the X-rays)
(thanks to Nathan for this question)
