Efficiency

Efficiency could mean:

 Energy efficiency, useful work per quantity of energy
 Energy conversion efficiency, desired energy output per energy input
 Energy conservation, reducing the use of energy
 Electrical efficiency, useful power output per electrical power consumed
 Fuel efficiency, converting energy in fuel to kinetic energy or work
 Specific impulse, in propulsion systems, a measure of fuel-efficiency
 Volumetric efficiency, in internal combustion engine design
 Lighting efficiency, visible light from a light source per unit of power, in lumens per watt
 Mechanical efficiency, the effectiveness of a simple machine, mechanical advantage over ideal mechanical advantage
 Thermodynamic efficiency, useful work per change in heat
 Exergy efficiency, measure of 2nd-law themodynamic loss
 Thermal efficiency, useful work per the higher heating value of the fuel
 Radiation efficiency, ratio of radiated power to power absorbed at the terminals of an antenna
 Efficiency (aerodynamics), for fixed wing aircraft the Lift-to-drag ratio
 Efficiency (economics), a general term, to capture the amount of waste or other undesirable features
 Pareto efficiency, making one individual better off, without making any other individual worse off
 Kaldor-Hicks efficiency, like a less stringent Pareto efficiency
 Allocative efficiency, an optimal distribution of goods
 The optimisation of a social welfare function
 Efficiency wages, paying workers more than the market rate for increased productivity
 Efficiency (statistics), a measure of desirability of an estimator
 Efficiency ratio, expenses as a percentage of revenue, etc.
 Efficiency Movement, of the Progressive Era 1890-1932, advocated efficiency in the economy, society and government
 Material efficiency, compares material requirements between construction projects or physical processes
 Textual efficiency, density of a message
 Algorithmic efficiency, the speed and space requirements of a computer program
 Quantum efficiency, a measure of sensitivity of a photosensitive device: the percentage of photons hitting the photoreactive surface that will produce an electron–hole pair

Category:Engineering concepts