Light an EM spectrum

Physics

white light

can refracted (bent) through a prism into separate wavelengths

Types of colours in white light (in order)

red, orange, yellow, green, blue, indigo, violet (ROYGBIV)

EM stands for

Electromagnetic

EM spectrum

our eyes can only see a small part of the EM spectrum (visible light)

A: Grammar rays

B: X- rays

C: Ultraviolet rays (UV)

D: infrared rays

E: microwave rays
F: radio rays
G: visible light
H: high energy
I:low energy

what is a sound wave

a longitudinal wave

sound waves ability to travel

travel through solids, liquids and gases, but are unable to travel through a vacuum

speed of sound waves in air

330 m/s to 350 m/s, depends on temperature

what is a EM wave

transverse wave

EM waves ability to travel

unable to travel through some substances but can travel through a vacuum

speed of EM waves in air

about 300.000,000 m/s

analogue quantities

• can have any value

• can change continually over time

digital quantities

• can have only particular values

• are represented by numbers

FM

frequency modulation - meaning frequency is changing

AM

amplitude modulation - meaning amplitude is changing

digital

has stronger signals and other signals from different sources cannot interfere

analogue

has weaker signals, other signals can interfere with it leading to original signals becoming distorted