Electromagnetic Waves Flashcards
Electro magnetic, waves longitudinal, or transverse
Transverse
Why are EM waves not mechanical
They can travel through a vacuum
What do EM waves transfer from the source to an absorber?
Energy
List the different types of waves in the EM spectrum in order of decreasing wavelength
(Increasing frequency)
Radio microwave, infrared, visible, ultraviolet, x-rays, gamma
Which parts of the EM spectrum can human see?
Visible light
How can lecturing magnetic waves be produced?
Changes inside an atom/atomic nucleus
How are gamma rays produced?
Changes in the nucleus of an atom for example, during radioactive decay
How can radio waves be produced?
Oscillations in an electrical circuit
How can we direct radio waves?
Waves are absorbed and create an alternating current with the same frequencies as the radio wave
What a radio waves used for
Transmitting television, mobile phone, and Bluetooth signals
What are microwaves used for?
Satellite communications cooking food
What is infrared radiation used for?
Heating remote controls, infrared cameras, cooking food
Which types of EM waves are harmful to the human body
Ultraviolet, x-rays, gamma rays
What are the hazards of being exposed to ultraviolet radiation?
Damage, skin cells, sunburn, increase risk of skin, cancer, age, prematurely,blindness
Why are x-rays used for medical imaging?
They passed through flesh but not bone
Why a gamma rays used for treating cancer and and sterilizing medical equipment
High doses, kill cells, and bacteria
What is refraction
Wave changes, speed and direction as they cross the boundary from one substance to another due to the change in velocity
What happens to the direction of a refracted EM wave when it slows down as it crosses the boundary from one substance to another
Benz towards the normal
