Voltage (Potential Difference) is the change in energy (work done) to each coulomb of charge between two points on a circuit, or two points across an electric field
V = ĪE/Q
Ohm's Law & Resistance
Power
Internal Resistance of a Battery
Batteries can be thought of as having an ideal voltage supply E.M.F. (Electromotive Force) in series with an internal resistance
V = š - Ir
How to find the internal resistance of a
battery
Kichhoff's Laws
Kirchhoff’s Current Law “At any junction in a circuit, the total current entering the junction equals the total current leaving the junction” Kirchhoff’s Voltage Law “Around any closed path of a circuit, the total of all the potential differences, V, is zero”
Particle displacement in the medium is parallel to the direction of wave propagation e.g. sound waves, primary earthquake waves
Transverse Waves
Particle displacement in the medium is perpendicular to the direction of wave propagation e.g. light and other electromagnetic waves, secondary earthquake waves
Wave Speed
v = fš
Superposition of Waves
Waves travel through each other and the total amplitude at any moment is equal to the sum of amplitudes of the individual waves.
Standing Waves
In musical instruments - when a reflected wave travels back through itself causing fixed points of Nodes (Deconstructive Interference) and Antinodes (Constructive Interference) due to the fractional relationship between the wavelength (š) of the wave and the length (L) of the resonating chamber
Standing Waves on a String
1st Harmonic
2nd Harmonic
3rd Harmonic
4th Harmonic
š = 2L
š = L
š = ⅔ L
š = ½ L
f = f1st
f = 2f1st
f = 3f1st
f = 4f1st
Standing Waves in a Pipe
Standing Waves on a 2D Plate
Cymatics
Doppler Effect
the observed increase or decrease in frequency of waves (e.g. sound, light) due to the relative movement of the source of waves to the observer
