Electromagnetic waves-P12 Flashcards
Are electromagnetic (EM) waves longitudinal or
transverse waves?
transverse
Explain why EM waves are not mechanical waves.
they can travel through a vacuum (don’t need a substance to travel through)
What do EM waves transfer from their source to an
absorber?
Energy
List the different types of waves in the EM spectrum
in order of decreasing wavelength (increasing
frequency).
radio, microwave, infared, visible, ultraviolet, x-rays, gamma
Which part of the EM spectrum can humans see?
visible light
How can electromagnetic 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 we detect radio waves?
waves are absorbed and create an alternating current
with the same frequency as the radio wave
How can radio waves be produced?
oscillations in an electrical circuit
What are 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 skin prematurely, blindness
Why are X-rays used for medical imaging?
they pass through flesh but not bone
Why are gamma rays used for treating cancer and
sterilising medical equipment?
high doses kill cells and bacteria
