Resistance, Ohmic. True resistance measured in ohms as distinguished from counter electro-motive force. (See also [Ohmic Resistance].)
Resistance, Spurious. The counter-electro-motive force. In its effect of opposing a current and in resisting its formation it differs from true resistance. True resistance diminishes current strength, absorbs energy, and develops heat. Spurious resistance opposes and diminishes a current without absorption of energy or production of heat.
Resistance, Standard. A known resistance employed to determine unknown resistances by comparison.
Resistance, True. The true resistance measured in ohms as distinguished from counter-electro-motive force.
Resonator, Electric. A small, open electric circuit with ends nearly touching. When exposed to electric resonance, or to a sympathetic electric oscillating discharge, a spark passes across the gap. The spark is due to inductance in the resonator.
Retentiveness. That property which enables steel to retain its magnetism.
Return. A line or conductor which carries current back to its starting-point after it has traversed a circuit. The best definition of a return is a circuit on which no new apparatus is installed.
Return-circuit. (See [Circuit, Return].)
Return-circuit, Railway. A grounded circuit used in trolley systems for ground returns through the tracks, they being joined by links or flexible wires so as to form perfect conductors. It is the negative side of the system, the positive being in the overhead or underground feed-wire or rail.
Reversibility. The principle by which any form of generator for producing a given form of energy may be reversed to absorb energy. The dynamo of the reversible type driven to generate current may be reversed and will develop power if a current is run through it.