Op

Op Amp
Abbreviation of Operational Amplifier.
Opacity
The condition of being non-transparent.
Opaque
Substances that do not transmit (pass) any light rays.
Open Circuit
A circuit that does not provide a complete path for the flow of current.
Open Circuit Voltage
The voltage between the terminals of a battery or power source when no current is flowing.
Open Crank Engine
Early internal combustion engines were of the open crank style, ie there was no enclosed crankcase.
Open Differential
Standard differential with no limited slip or torque sensing features, allows unlimited wheelspin.
Open Interval
An interval that does not include its two endpoints.
Open Loop
A system operating without feedback.
Open Loop Fuel Control
A mode where engine input air/fuel ratio is controlled by measuring the mass of input air and adding the proper mass of fuel to obtain a desired ratio.
Open Loop Gain
Gain of an amplifier when no feedback is present.
Open System
A system which can exchange both matter and energy with its surroundings.
Open Window Unit
The original name for the Sabin.
OpenGL
A graphics standard providing advanced rendering capabilities.
Operand
A word on which an operation is to be performed.
Operating Point
That point in the characteristics of a tube or transistor around which the signal voltages vary.
Operating Pressure
Pressure at which a system is operating.
Operating Stress
Stress imposed on a part in service.
Operating System
The master program that runs automatically when you switch the computer on and is responsible for the many routine tasks required to keep a computer running.
Operational Amplifier
One of the basic building blocks of analogue circuits.
Opposed Piston Engine
An engine that has two pistons within the same cylinder, traveling in opposite directions.
Opposite Faces
Faces that lie in parallel planes.
Opposition
The point at which a planet that is further away from the Sun than the Earth.
Optic Axis
A line passing through the center of a curved mirror and the center of the sphere from which the mirror is made.
Optical Activity
A substance that is capable of rotating plane-polarized light.
Optical Alignment
A secondary alignment method for determining on-line and off-line changes in alignment conditions.
Optical Axis
A line passing through the centres of curvature of a lens or series of lenses in an optical system.
Optical Cavity
Space between the laser mirrors where lasing action occurs.
Optical Coupler
A coupler composed of an LED and a photodiode and contained in a lightconducting medium.
Optical Double Star
Two stars in nearly the same line of sight but differing greatly in distance from the observer.
Optical Encoder
A linear or angular position feedback device using light fringes to develop position information.
Optical Filter
A device used to reject certain frequencies of light.
Optical Flat
A piece of glass with one or both surfaces polished flat.
Optical Illusion
A drawing or object that appears to have an effect that it does not really have, such as when a flat painting seems to have three-dimensional depth.
Optical Interference
The interaction of two light waves on the total intensity of light.
Optical Isomers
Stereoisomers that exist because of the presence of chiral centres.
Optical Pumping
The excitation of the lasing medium by the application of light rather than electrical discharge.
Optical Pyrometer
An instrument for measuring the temperature of heated material.
Optical Transmission
To admit the passage of light through a medium; light not reflected back to its source is transmitted through the medium.
Optics
Lists all the Optics topics
Optics Calculations
Lists all Optics Calculations in the Encyclopaedia
Optics Conversions
Lists all Optics Conversions in the Encyclopaedia
Optics Weblinks
Lists all Optics Weblinks in the Encyclopaedia
Optimum Working Frequency
The most practical operating frequency that can be used with the least amount of problems.
Opto-Coupler
Any device that functions as an electrical-to-optical or optical-to-electrical transducer.
Opto-Isolated
System or circuit that transmits signal with no direct electrical connections, using photoelectric coupling between elements.