Lecture 1- Light Flashcards
What is light?
- form of energy
- a form of radiation
- electromagnetic wave- transverse wave
What is an electromagnetic wave?
a wave in which the electric field and the magnetic field are oscillating perpendicular to the direction/motion of the wave.
What is a transverse wave?
light
which means the 2 components oscillate perpendicular to its direction of propagation
What is a longitudinal wave?
a wave vibrating in the direction of propagation/wave/
What do the waves in the electromagnetic spectrum have?
- an electric and magnetic component
- oscilate perpendicular to its direction of propagation
What ray has the most energy?
Gamma ray- highest energy and smallest wavelength
What does the visible spectrum go from?
400-700nm
What are the properties of EM waves?
Wavelength
Amplitude
Speed
Frequency
How can EM waves be described?
by certain speeds and frequency
What is Speed?
(v) -
the rate of travel of a wave in a certain direction
What is frequency?
the number of complete waves generated per second
Hz
What is wavelength?
the distance between one peak on a wave to the same point/peak on a successive wave
(m)
What is amplitude?
the maximum distance of the wave measured from the line of equilibrium to the peak or trough of the wave
(m)
What is unpolarised light?
Both electric and magnetic fields vibrate in any random orientation plane perpendicular to the direction of propagation.
What is polarised light?
it oscillates in only ONE direction
has a polarising filter , which has molecules, aligned to allow the electric field along the one axis to get through
