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resin A natural or synthetic organic substance
that is polymeric in structure and largely amorphous.
Various plastics are made from synthetic
resins.
resistance 1. Symbol, R or r. Unit, ohm. In a device,
component, or circuit, the simple opposition
to current flow. Resistance by itself causes no
phase shift. In a purely resistive circuit, R = E/I,
where R is the resistance in ohms, E is the voltage
in volts, and I is the current in amperes. 2. A
property of circuits, devices, or substances that
causes impinging energy to be dissipated by conversion
to heat. Compare REACTANCE.
resistance
Per kilometer of solid copper wire for American Wire Gauge
(AWG) 1 through 40.
AWG ohms/km AWG ohms/km
1 0.42 21 43
2 0.52 22 54
3 0.66 23 68
4 0.83 24 86
5 1.0 25 110
6 1.3 26 140
7 1.7 27 170
8 2.1 28 220
9 2.7 29 270
10 3.3 30 350
11 4.2 31 440
12 5.3 32 550
13 6.7 33 690
14 8.4 34 870
15 11 35 1100
16 13 36 1400
17 17 37 1700
18 21 38 2200
19 27 39 2800
20 34 40 3500
resistance alloys Metallic alloys used in the manufacture
of resistance wire and resistance elements.
Such alloys include CONSTANTAN,
GERMAN SILVER, MANGANIN, MONEL METAL,
and NICHROME.
resistance balance A device used to balance a circuit,
by means of the insertion of resistances.
resistance brazing A method of brazing in which
metal is heated by passing a current through it.
The I 2 R loss, or dissipated power, occurs in the
form of heat.
resistance bridge A bridge (see BRIDGE, 2) for
measuring resistance only.
resistance-capacitance Abbreviation, RC. Pertaining
to a combination of resistance and capacitance
(e.g., RESISTANCE-CAPACITANCE CIRCUIT).
resistance-capacitance bridge 1. A four-arm null
circuit containing only resistors and capacitors.
Also see BRIDGE, 1. 2. An alternating-current
bridge (see BRIDGE, 2) for measuring resistance
and capacitance.
resistance-capacitance circuit A circuit containing
only resistors and capacitors. There are no inductors.
resistance-capacitance-coupled amplifier A
multistage amplifier circuit in which RESIS-
TANCE-CAPACITANCE COUPLING is used between
stages and at the input and output points
of the circuit.
resistance-capacitance coupling Coupling, especially
between stages in a circuit, using blocking
capacitors and supply-path resistors.
resistance-capacitance filter A power-supply filter
or wave filter containing only resistors and capacitors.
The resistors are in the positions
occupied by inductors in inductance-capacitance
filters.
resistance-capacitance-inductance Abbreviation,
RCL. Pertaining to a combination of resistance,
capacitance, and inductance.
resistance-capacitance phase shifter A phase
shifter containing only resistors and capacitors to
obtain the desired shift.
R
C
E R E C
+
E R
0
E C −
resistance-capacitance phase shifter
resistance-capacitance time constant Symbol, t.
The time constant (see ELECTRICAL TIME CON-
STANT) of a circuit containing (ideally) only resistance
and capacitance; t = RC, where t is in
seconds, R is in ohms, and C is in farads. Compare
RESISTANCE-INDUCTANCE TIME CONSTANT.
resistance-capacitance tuning Tuning of a circuit,
such as that of an amplifier or oscillator, by
means of a variable resistor or ganged units of
this type. See, for example, PARALLEL-TEE AM-
PLIFIER, PARALLEL-TEE OSCILLATOR, and
WIEN-BRIDGE OSCILLATOR.
resistance-coupled amplifier See RESISTANCE-
CAPACITANCE-COUPLED AMPLIFIER.
resistance drop The voltage drop across a resistor,
or across the inherent resistance of a device.
resistance-inductance Abbreviation, RL. Pertaining
to a combination of resistance and inductance
(e.g., RESISTANCE-INDUCTANCE CIRCUIT).
resistance-inductance bridge 1. A four-arm null
circuit containing only resistors and inductors.
Also see BRIDGE, 1. 2. An alternating-current
bridge (see BRIDGE, 2) for measuring resistance
and inductance only.
resistance-inductance circuit A circuit containing
only resistors and inductors. There are no capacitors.