Light and the Electromagnetic Spectrum Flashcards
Uses of the Electromagnetic Spectrum
Radio
Microwave
X-ray
Gamma rays
Relationships
as speed is constant for all EM waves in a vacuum
As wavelength decreases, frequency must increase
As frequency increases, energy of wave increases
Electromagnetic Waves
Transfer energy from source to observer
Transverse waves
All travel in a same speed in a vacuum
Images (Physics only)
A real image is an image produced at the opposite side of the lens to the object
Convex lenses
Fatter at centre
Focuses light inwards
Horizontal rays focus onto focal point
Concave lenses
“Caves Inward”
Spreads light outwards
Light appear from focal point
Thinner at centre than at edges
Lenses (2)
Shorter focal length, greater power
Thicker lens means thicker focal length, so greater power
Lenses
Focal length is the distance between the lens and the focal point
Focal point is the point where all horizontal rays meet
Colour (Physics only)
Each colour is a certain wavelength in visible light
All the colours together make up white light
Specular reflection
Mirror reflection, following the law of reflection
smooth surface (all light incident and the same angle)
Total Internal Reflection (TIR)
Occurs when the light is passing from a denser medium into a less dense medium
The light internally reflects back into the glass
Refraction
is the redirection of a wave as it passes from one medium to another
Reflection
Incident angle = reflection angle
Angles are always measured from normal
Ray Diagram
Arrows show direction of light travelling
Incident angle is the angle of the entering ray
reflecting angle is the angle of the Exiting ray
