EMR(Electro-Magnetic Radiation) Flashcards
What are the three types of EMR that are ionising?
X-rays
Ultra violet radiation
Gammar Rays
What are the five types of non-ionising EMR waves?
Visible Light Infra red radiation Microwaves Radio Waves Low frequency waves
Define radiation
Radiation is a particle or wave that travels through space
Radio waves have a wavelength of?
2km-1m
Microwaves have a wavelength of?
1m-1mm
Infra red has a wavelength of?
1mm-750nm
Visable light has a wavelength of?
750nm-480nm
Ultra violet has a wavelength of?
480nm-100nm
X-rays have a wavelength of?
100nm-10nm
Gammar rays have a wavelength of?
10nm-10pm
What is the speed of light?
3x10*m/s
*=8
What colours do white object reflect?
All colours
What colours does black reflect?
None
What colour is reflected off coloured items?
The colour which they appear
What can happen to light when it hits an object?
It can be absorbed, reflected or transmitted
What does something that transmits all light look like?
Clear
How to filters work? Colour addition or colour subtraction?
Colour subtraction
When mixing light we are using?
Colour addition
Radio waves are used in?
Communication
Microwaves are used in
Mobile phones
Microwave ovens
Infra red are used in
Healing sports injuries
Tv remote controls
Night vision goggles
What is visible light used in
Light bulbs
DVD players
Laser printers
Ultra violet is used in
Sterilising food
Killing microbes
Skin tanning
X-rays are used in
Airport security
Astronomy
See inside people
Gammar rays are used in
Cancer treatment
Radio therapy
What is the formula for speed of a wave?
Speed=frequency x wavelength
What does AM stand for
Amplitude modulation
How dies AM work?
AM changes the amplitude of the carrier wave
What does FM stand for
Frequency modulation
How does FM work?
FM change the frequency of the carrier wave
Which travels further AM or FM?
AM
What do ADSL modems use to send information?
Digital signal
What do optic fibre modems use to send a signal?
Light pulses along glass fibres
What EMR do TVs use?
Radio waves
Do TVs have a digital or analogue signal?
Digital
What type of EMR do mibile phones use?
Microwaves
Explain how a message gets from one mobile phone to another
Mobile phone sends a message to a base station which is in line of sight of the sender. The message is then moved between the base station to another using a copper cable, optic fibre or satellites. It is then distributed to the receiving phone.
Can all EMR be reflected, bent or make a shadow?
Yes
