physics terminology for waves and electricity

Reactance

The opposition offered by an inductor or capacitor to the flow of alternating current due to a phase shifted back emf or stored charge

Impedance

The total effective opposition to alternating current in a circuit containing both resistive and reactive components

Resonance - electricity

The unique operating state of a series LCR circuit where the driving supply frequency causes inductive reactance and capacitive reactance to become equal in magnitude

EMF

Voltage across a power supply when no current is drawn

Kirchoffs current law

Total current entering a junction = total current leaving a junction

Kirchoffs voltage law

The total of all the voltages in a closed loop is equal to zero

Len’z law

The direction of the induced current creates a force that opposes the change that produces it

Faradays law

The induced voltage in a coil is the sum of the number of loops and the rate at which the magnetic field changes

Resonance - waves

Oscillation when frequency of forced vibration is same as natural frequency

Principle of superposition

When 2 or more waves occupy the same position in space at the same time, the resultant displacement at any point is the vector sum of the individual wave displacements

Coherence

A state where 2 or more wave sources emit waves of the same frequency and wavelength with a constant phase relationship

Path difference

The physical difference in distance travelled by 2 waves from their respective sources to a common point of arrival

Constructive interference

Where 2 waves arrive at a point in phase adding their amplitudes together to produce a wave of maximum resultant amplitude - forming bright fringes or loud sound spots

Destructive interference

Where 2 waves arrive at a point out of phase, phase difference = 180 cancelling their amplitudes to produce zero or minimum resultant amplitude - forming dark fringes or quiet sound spots

Standing/stationary wave

A wave pattern characterised by fixed positions of zero amplitude and maximum amplitude formed when 2 identical travelling waves of equal frequency, wavelength and amplitude moving in opposite directions undergo continuous superposition

Fundamental frequency

The lowest possible natural frequency at which a medium can form a standing wave, corresponding to the simplest mode of vibration

Closed pipe

A tube or air column closed at one end and open at the other requiring a displacement node at the closed end and a displacement antinode at the open end supporting only odd harmonics

Doppler effect

The apparent shift in the observed frequency of a wave caused by relative motion between the wave source and an observer

Beats

Regular pulsations in sound intensity (loud and quiet) heard when 2 sound waves of slightly different frequencies (f1 and f2) occupy the same space