Resistance: Symbol = ' R' or r. Unit, "ohm".
1.In a device,component, or circuit, the simple oppositionto 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 voltagein volts, and I is the current in amperes.
2. Aproperty of circuits, devices, or substances that
causes impinging energy to be dissipated by conversion
to heat.
3.Every resistor have some different colours that mean resistor have coding that is called colour coding above shown in above figure resistor is as their on resistor we seeing some colours that is called colour coding.
causes impinging energy to be dissipated by conversion
to heat.
3.Every resistor have some different colours that mean resistor have coding that is called colour coding above shown in above figure resistor is as their on resistor we seeing some colours that is called colour coding.
Compare 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 I2R 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 RESISTANCE-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.
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 phaseshifter containing only resistors and capacitors to obtain the desired shift.
resistance-capacitance phase shifter
resistance-capacitance time constant: Symbol, t.The time constant (see ELECTRICAL TIME CONSTANT) 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 AMPLIFIER,PARALLEL-TEE OSCILLATOR, and
WIEN-BRIDGE OSCILLATOR
resistance-coupled amplifier:
ee RESISTANCECAPACITANCE-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
resistance-inductance phase shifter • resistors in series-parallel
resistance-inductance phase shifter A phase shifter containing only resistors and inductors to
obtain the desired phase shift.
resistance lamp An incandescent bulb inserted in series with a circuit to provide a dropping resistance.Such a lamp is capable of dissipating a large amount of power, shows very little reactance at low frequencies, and is inexpensive.
resistance material A substance, such as carbon or German silver, whose resistivity is high enough to enable its use as a lumped resistor.See, for example, RESISTANCE ALLOYS and RESISTANCE METAL.
resistance metal A metal, such as iron, whose resistivity is high enough to enable its use as a lumped resistor. Also see RESISTANCE ALLOYS.
resistance pad An attenuator composed of noninductive
resistors.
resistance standard A highly accurate and stable resistor used in precision measurements of resistance. Also see PRIMARY STANDARD and SECONDARY STANDARD.
resistance strain gauge An electrical strain gauge in which the stressed element is a thin resistance wire.
resistance strip A strip of metallic or nonmetallic resistance material. Also see RESISTANCE ALLOYS and RESISTANCE METAL.
resistance temperature detector A transducer consisting of a specially made resistor whose resistance varies linearly with temperature.
resistance thermometer An electronic thermometer whose operation is based on the change of resistance of a wire as it is heated or cooled.
resistance transducer See RESISTIVE TRANSDUCER.
resistance tuning See VARIABLE-RESISTANCE TUNING.
resistance welding An electrical or electronic welding process in which the workpieces are heated by current flowing through the inherent resistance of their junction.
resistance wire Wire made of a metal or alloy that exhibits significant resistivity. See, for example,
RESISTANCE ALLOYS and RESISTANCE METAL.
resistance-wire sensor A specific length of resistance wire, properly mounted, whose resistance is proportional to a sensed phenomenon (such as strain, temperature, presence of gas, pressure,etc.). See, for example, ELECTRICAL STRAIN
GAUGE, GAS DETECTOR, and PRESSURE TRANSDUCER.
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