Amplitude is the magnitude of change in the oscillating variable, with each oscillation, within an oscillating system. Peak to Peak Charter School is a K-12 public College-preparatory Charter school located in Lafayette, Colorado, and is part of the The magnitude of a mathematical object is its size a property by which it can be larger or smaller than other objects of the same kind in technical terms an Ordering Oscillation is the repetitive variation typically in Time, of some measure about a central value (often a point of Equilibrium) or between two or more different states For instance, sound waves are oscillations in atmospheric pressure and their amplitudes are proportional to the change in pressure during one oscillation. Sound' is Vibration transmitted through a Solid, Liquid, or Gas; particularly sound means those vibrations composed of Frequencies Pressure (symbol 'p' is the force per unit Area applied to an object in a direction perpendicular to the surface If a graph of the system is drawn with the oscillating variable as the vertical axis and time as the horizontal axis then the amplitude may be measured as the vertical distance between points on the curve.

Concepts of Amplitude

Peak Amplitude

Peak amplitude is measured between a peak and the rest position of the system. In many sciences this is called peak amplitude. In astronomy, when measuring the wobble of a body due to the gravitational influence of another body, it is called the semi-amplitude[1]. Astronomy (from the Greek words astron (ἄστρον "star" and nomos (νόμος "law" is the scientific study

The displacement y is the amplitude of the wave

Peak-to-peak Amplitude

Peak-to-peak amplitude is to measure it between peak and trough. Peak-to-peak amplitudes can be measured by meters with appropriate circuitry, or by viewing the waveform on an oscilloscope. In the Physical sciences Quality assurance, and Engineering, Measurement is the activity of obtaining and comparing physical quantities An oscilloscope (commonly abbreviated to scope or O-scope) is a type of Electronic test equipment that allows signal Voltages to be viewed

Root Mean Square Amplitude

Root mean square(RMS) amplitude is used especially in electrical engineering: the RMS is defined as the square root of the mean over time of the square of the vertical distance of the graph from the rest state. In Mathematics, the root mean square (abbreviated RMS or rms) also known as the quadratic mean, is a statistical measure of the Electrical engineering, sometimes referred to as electrical and electronic engineering, is a field of Engineering that deals with the study and application of In Mathematics, a square root of a number x is a number r such that r 2 = x, or in words a number r whose In Statistics, mean has two related meanings the Arithmetic mean (and is distinguished from the Geometric mean or Harmonic mean

Ambiguity of Amplitude

The use of peak amplitude is simple and unambiguous for symmetric, periodic waves, like a sine wave, a square wave, or a triangular wave. A square wave is a kind of Non-sinusoidal waveform, most typically encountered in Electronics and Signal processing. For an asymmetric wave (periodic pulses in one direction, for example), the peak amplitude becomes ambiguous because the value obtained is different depending on whether the maximum positive signal is measured relative to the mean, the maximum negative signal is measured relative to the mean, or the maximum positive signal is measured relative the maximum negative signal (the peak-to-peak amplitude) and then divided by two.

For complex waveforms, especially non-repeating signals like noise, the RMS amplitude is usually used because it is unambiguous and because it has physical significance. For example, the average power transmitted by an acoustic or electromagnetic wave or by an electrical signal is proportional to the square of the RMS amplitude (and not, in general, to the square of the peak amplitude). In Physics, power (symbol P) is the rate at which work is performed or energy is transmitted or the amount of energy required or expended for Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter.

A sinodial voltage.
1 = Amplitude (peak),
2 = Peak-to-peak,
3 = RMS,
4 = Wave period

When dealing with alternating current electrical power it is universal to specify RMS values of a sinusoidal waveform. Amplitude is the magnitude of change in the oscillating variable with each Oscillation, within an oscillating system In Mathematics, the root mean square (abbreviated RMS or rms) also known as the quadratic mean, is a statistical measure of the Frequency is a measure of the number of occurrences of a repeating event per unit Time. An alternating current ( AC) is an Electric current whose direction reverses cyclically as opposed to Direct current, whose direction remains constant Electric power is defined as the rate at which Electrical energy is transferred by an Electric circuit. It is important to recognise that the peak-to-peak voltage is nearly 3 times the RMS value when assessing safety, specifying components, etc.

Pulse amplitude

In telecommunication, pulse amplitude is the magnitude of a pulse parameter, such as the field intensity, voltage level, current level, or power level. In Signal processing, the term pulse has the following meanings A rapid transient change in the amplitude of a signal from a baseline value to a higher In Physics, the field strength of a field is the magnitude of its vector value Electrical tension (or voltage after its SI unit, the Volt) is the difference of electrical potential between two points of an electrical Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. In Physics, power (symbol P) is the rate at which work is performed or energy is transmitted or the amount of energy required or expended for

Note 1: Pulse amplitude is measured with respect to a specified reference and therefore should be modified by qualifiers, such as "average", "instantaneous", "peak", or "root-mean-square. In Mathematics, the root mean square (abbreviated RMS or rms) also known as the quadratic mean, is a statistical measure of the "

Note 2: Pulse amplitude also applies to the amplitude of frequency- and phase-modulated waveform envelopes. Frequency is a measure of the number of occurrences of a repeating event per unit Time. The phase of an oscillation or wave is the fraction of a complete cycle corresponding to an offset in the displacement from a specified reference point at time t = 0 waveformogg|right|a sine square and sawtooth wave at 440 hz]] Waveform means the shape and form of a signal such as a Wave moving in a solid liquid or gaseous

Source: from Federal Standard 1037C

Amplitude in the Wave Equation

In the simple wave equation

A is the amplitude of the wave. Federal Standard 1037C, entitled Telecommunications Glossary of Telecommunication Terms is a United States Federal Standard issued by the General Services Administration The wave equation is an important second-order linear Partial differential equation that describes the propagation of a variety of Waves such as Sound waves Waves and hertz are used><

Units of Amplitude

The units of the amplitude depend on the type of wave.

For waves on a string, or in medium such as water, the amplitude is a displacement. A Vibration in a string is a Wave. Usually a vibrating string produces a Sound whose Frequency in most cases is constant Water is a common Chemical substance that is essential for the survival of all known forms of Life. In Physics, displacement is the vector that specifies the position of a point or a particle in reference to a previous position or to the origin of the chosen

The amplitude of sound waves and audio signals (also referred to as Volume) conventionally refers to the amplitude of the air pressure in the wave, but sometimes the amplitude of the displacement (movements of the air or the diaphragm of a speaker) is described. Sound' is Vibration transmitted through a Solid, Liquid, or Gas; particularly sound means those vibrations composed of Frequencies Particle displacement or particle amplitude (represented in Mathematics by the lower-case Greek letter &xi) is a Measurement For the Marty Friedman album see Loudspeaker (album A loudspeaker, speaker, or speaker system is an electroacoustical The logarithm of the amplitude squared is usually quoted in dB, so a null amplitude corresponds to -∞ dB. In Mathematics, the logarithm of a number to a given base is the power or Exponent to which the base must be raised in order to produce The decibel ( dB) is a logarithmic unit of measurement that expresses the magnitude of a physical quantity (usually power or intensity relative to Infinity (symbolically represented with ∞) comes from the Latin infinitas or "unboundedness Loudness is related to amplitude and intensity and is one of most salient qualities of a sound, although in general sounds can be recognized independently of amplitude. Loudness is the quality of a Sound that is the primary psychological correlate of physical strength (amplitude In Physics, intensity is a measure of the time-averaged Energy Flux. Sounds and noises are only separated by the experience of the listener The square of the amplitude is proportional to the intensity of the wave. The sound intensity, I, (acoustic intensity is defined as the Sound power Pac per unit area A.

For electromagnetic radiation, the amplitude of a photon corresponds to the changes in the electric field of the wave. Electromagnetic radiation takes the form of self-propagating Waves in a Vacuum or in Matter. In Physics, the space surrounding an Electric charge or in the presence of a time-varying Magnetic field has a property called an electric field (that can However radio signals may be carried by electromagnetic radiation; the intensity of the radiation (amplitude modulation) or the frequency of the radiation (frequency modulation) is oscillated and then the individual oscillations are varied (modulated) to produce the signal. Amplitude modulation ( AM) is a technique used in electronic communication most commonly for transmitting information via a Radio Carrier wave

Wave Forms and Amplitude

The amplitude may be constant (in which case the wave is a continuous wave) or may vary with time and/or position. A continuous wave or continuous waveform ( CW) is an Electromagnetic wave of constant Amplitude and Frequency; and in Mathematical The form of the variation of amplitude is called the envelope of the wave. An envelope detector is an electronic circuit that takes a high-frequency signal as input and provides an output which is the "envelope" of the original signal

If the waveform is a pure sine wave, the relationships between peak-to-peak, peak, mean, and RMS amplitudes are fixed and known, but this is not true for an arbitrary waveform which may or may not be periodic. In Mathematics, the root mean square (abbreviated RMS or rms) also known as the quadratic mean, is a statistical measure of the

For a sine wave the relationship between RMS and peak-to-peak amplitude is:

References

[1]Exoplanets by Urial A. Goldvais downloaded 2008/03/31 from img2. tapuz. co. il/forums/1_109580628. pdf

See also

• Waves and their properties:
  • Frequency
  • Period
  • Wavelength
  • Crest factor
• Amplitude modulation