"A",
"B",
"C",
"D",
"E",
"F",
"G",
"H",
"I",
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"M",
"N",
"O",
"P",
"Q",
"R",
"S",
"T",
"U",
"V",
"W",
"X",
"Y",
"Z"
Previous section of "A" terms and definitions
APOGEE. The point in the orbit of a satellite the greatest distance from the earth.
APPARENT DRIFT. The effect of the earth’s rotation on a gyro that causes the spinning axis to appear to make one complete rotation in one day. Also called APPARENT PRECESSION or APPARENT
ROTATION
APPARENT POWER. That power apparently available for use in an ac circuit containing a reactive element. It is the product of effective voltage times effective current expressed in volt-amperes. It must be multiplied by the power factor to obtain true power available.
ARMATURE. In a relay, the movable portion of the relay. The windings in which the output voltage is generated in a generator or in which input current creates a magnetic field that interacts with the main field in a motor.
ARMATURE LOSSES. Copper losses, eddy current losses, and hysteresis losses that act to decrease the efficiency of armatures.
ARMATURE REACTION. The effect in a dc generator of current in the armature creating a magnetic field that distorts the main field and causes a shift in the neutral plane.
ARTIFICIAL TRANSMISSION LINE. An LC network that is designed to simulate characteristics of a transmission line.
A-SCOPE. A radar display on which slant range is shown as the distance along a horizontal trace. [Radar Terms]
ASPECT RATIO. The ratio between the width of an object and the height of the object.
ASSEMBLY. A number of parts or subassemblies, or any combination thereof, joined together to perform a specific function.
ASTABLE MULTIVIBRATOR. A multivibrator that has no stable state. Also called free-running
because it alternates between two different output voltage levels during the time it is on. The frequency is determined by the RC time constant of the coupling circuit.
ASTIGMATISM. An aberration of a lens with spherical surfaces such that the image of a point not
lying on the optical axis is a pair of short lines normal to each other and at slightly different
distances from the lens. Radial and tangential lines are in focus in different image planes.
ASYMMETRICAL MULTIVIBRATOR. A multivibrator that generates rectangular waves.
ASYNCHRONOUS ORBIT. One where the satellite does not rotate or move at the same speed as the earth.
Next section of "At" definitions and terms
