Electromagnetic Waves Flashcards
What type of waves are electromagnetic waves?
Transverse waves
What do all types of electromagnetic waves do the same?
They all travel at the same velocity all at the speed of light in air or a vacuum
What are all the sections of the electromagnetic spectrum?
Extends from low frequency to low energy waves to high frequency to high energy waves
What does the wavelength of an electromagnetic wave effect?
How it is absorbed
What are the uses of radio waves ?
Television radio Bluetooth
What are the uses for microwaves?
What satellite communications and cooking food
What are the uses for infrared waves ?
Electrical heaters cooking food and infrared cameras
What are the uses for visible light
Fibre optic communications and general lighting of rooms
What are ultraviolet waves used for?
Energy efficient light bulbs security marking and sunbeds
What are x-rays for used for?
Medical imaging and treatments
What are gamma rays used for
Sterilising food and treatment of tumors
What are features of radio waves?
Radio waves are low energy waves and therefore not home for making them ideal for radio transmission
What are features of microwaves
Microwaves travel in straight lines through the atmosphere this makes them ideal for transmitting signals to satellites in orbit and transmitting them back down to the receivers
What are features of infrared waves?
electrical heaters grills or toasters and much more glow red hot as the electricity flows through them this transmits infrared energy that is absorbed by the food and converted back into heat
What can visible light do in fibre optics
Visible light can travel down optical fibres from one end to the other without being lost through the sides
What do ultraviolet waves do
the ultraviolet waves can be in energy efficient light bulbs UV waves are produced by gas in the ball when it is excited by the electric current these UV waves are absorbed by the coating on the bulb which fluresces giving off visible light
Why are x-rays perfect for medical imaging and treatments
x-rays are able to penetrate soft tissue but not bone a photographic plate behind the person which Shadows were bones are allows the x-ray to be a lot more clear
What can gamma rays be used to do
Gamma rays are the most energetic of all electromagnetic waves and can be used to destroy bacteria and tumours
What can radio waves be caused by
Oscillations
How is a radio signal produced
The frequency of the radio wave produced matches the frequency of the electrical oscillation
What is created when radio waves are absorbed by a conductor
Alternating currents
What can resort in em waves are otherwise known as electromagnetic waves
Changes in atoms and the nuclei of atoms
What can electrons moving between energy levels as a result of heat or electrical excitation cause
Waves for example infrared waves and visible light ultraviolet and x-ray etc
What do ultraviolet waves x-rays and gamma rays carry enough energy to do
Harm the human body
How is ultraviolet waves harmful
They can cause the skin to age prematurely and increase the risk of skin cancer
How can x-rays and gamma rays harm the human body
x-rays and gamma rays ionising radiation they can damage cells by ionizing atoms and if absorbed by the nucleus of the cell they can cause gene mutations and cancer
