PHYSICAL SCIENCE PLUS - ENERGY TRANSFER

Convection & Conduction Transfer of Energy through Waves Features of
Waves
Transmission of
Sound
The Electromagnetic Spectrum Absorption, Reflection & Refraction Revision
   
   
    Properties of
Electromagnetic Waves
 
   
    The Electromagnetic
Spectrum
 
   
    Test Your
Understanding
 
   
    Resources  
   
   


What is Electromagnetism?

A magnetic current is created from the movement of electrical current or vice versa (that is a magnetic field movement will create an electrical field). As such the two fields will continually move and continue to generate one another in the manner of a transverse wave.



What Factors determine the type of Eletromagnetic Radiation?


WAVELENGTH: the distance between two successive peaks or troughs within a wave. Measurements vary from kilometres (103 m) to less than one thousandth of a milimetre (<10-3 m).

FREQUENCY: the number of waves created each second and is measured in hertz (Hz).


   
Figure 1. Identifying wavelength using crests and troughs. From Wavelength definition by Tutor Circle, 2018 (http://physics.tutorcircle.com/waves/wavelength.html). Copyright 2018 by Tutor Circle.   Figure 2. Relationship between frequency & wavelength. From How are frequency and wavelength related, by Tutor Circle, 2018 (http://physics.tutorcircle.com/waves/frequency-and-wavelength.html). Copyright 2018 by Tutor Circle.  

Frequency, wavelength and speed work together in what is known as the wave equation to produce waves of different forms. As all types of radiation travel at the speed of light (300,000km/s) the equation dictates that:
      •   When frequency of a wave increases, wavelength will decrease
      •   When frequency of a wave decrease, wavelength will increase

All electromagnetic waves do not require a medium in which to move and can travel through liquids, gases, empty space & some solids - high frequency/high energy radiation can pass through most solids, while low frequency/low energy radiation can be stopped by simple solids.