Engineering ratios

ratio of active power to apparent power in an AC electrical system

measure comparing the level of a searched signal to the level of background noise

thumb|upright|Underdamped spring–mass system with

Ratio of the volume of a combustion chamber from its largest capacity to its smallest capacity

dimensionless measure for the damping of an oscillator

aerodynamic efficiency of how far an aircraft can move forward without engine power for every meter it sinks

ratio between the largest and smallest values that a certain quantity can assume, often used in the context of signals

measure of impedance matching of loads to the characteristic impedance of a transmission line or waveguide

ratio of an aircraft's wing span to its mean chord

mass ratio

dimensionless ratio of thrust to weight of a reaction engine or a vehicle with such an engine

calculation commonly applied to engines and mobile power sources

metric used to measure picture quality

telecommunications performance metric

ratio of a building's total floor area to the size of the plot

ratio between the mass flow rate of the bypass stream to the mass flow rate entering the core of a turbofan engine

factor by which an engineered system's capacity is increased over the expected requirement to ensure safety in the face of error or uncertainty

screen resolution measured in pixels per length

mode of flight of some heavier-than-air objects without use of thrust covering a greater distance horizontally than vertically, employed by gliding animals and by some aircraft

ratio of rejection of common mode signals to differential signals

property of photosensitive devices

ratio of useful heating or cooling provided to work required

material's strength (force per unit area at failure) divided by its density

measurement of the power of a data compression algorithm

loss of signal transmission power when devices are connected to a transmission line

proportion of observed intensity to ideal intensity, in astronomical imaging

main parameter determining concrete strength and durability

ratio of the mass density of a mixture drawn into a cylinder at atmospheric pressure to the mass density of the same volume of air in the intake manifold

proportion between the width and the height of a pixel

quotient of a product's performance delivery by its cost

quantity used to characterize performance

used to describe the type of heat transfer for a surface that has moisture

term

property of a display system

design parameter of gas turbines

mechanics term

thumb|right|280px|Bit-error rate (BER) vs E_b/N_0 curves for different [[digital modulation methods is a common application example of E_b/N_0. Here an AWGN channel is assumed.]]

the signal-to-noise ratio of a modulated signal

Measurement of an electronic circuit

ratio between a display's width and height

Measure for analyzing digitizing schemes

measurement used for wind turbines

information theory quantity