P6 - Waves 2 Flashcards
Whar type of spectrum do electromagnetic waves form ?
A continuous spectrum
Order the types of electromagnetic radiation from lowest to highest frequency.
- Radio waves
-Microwaves
-Infrared
-Visible light
-Ultraviolet
-X-rays
-Gamma rays
How do the speeds of EM radiation differ in a vacuum and in air?
Electromagnetic waves all travel at the same speed in a vacuum and in air
What property of waves in different mediums cause refraction ?
- Velocity
- Wave speed is slower in denser materials , causing refraction
In which direction ( relative to the normal ) do waves refract when entering a denser medium?
- They bend towards the normal
- when angle of refraction is less than the angle of incidence
What type of waves can be produced in oscillations in an electrical circuit ?
Radio waves
How can radio waves create an alternating current in a circuit?
When radio waves are abosrbed , they can induce oscillations in a circuit with the same frequency as the waves themselves.
Where do gamma rays originate from ?
They originate from changes in the nuclei of atoms
What health effects can ultraviolet waves cause?
- they can cause the skin to age prematurely
- they can increase the risk of developing skin cancer
What health effect can X-rays and Gamma rays cause?
- They are ionising radiation so can cause mutations in genes
- They can lead to increased risk of developing various cancers
Give three practical uses for infrared radiation.
- Electrical heaters
- Cooking food
- Infrared cameras
Give two practical uses for microwave radiation
- Satellite communications
- Cooking food
Give two practical uses for radio waves.
- Television transmission
- Radio transmission
What are Electromagnetic waves ?
Transverse waves that transfer energy from the source of the waves to an absorber
How are the waves that form the EM spectrum grouped?
In terms of their wavelength and their frequency
