reactancen.
/rɪˈakt(ə)ns/, U.S. /riˈæktns/ 1.
a. The non-resistive component of electrical impedance, arising from the effect of inductance or capacitance or both and causing the current to be out of phase with the electromotive force causing it.Impedance can be expressed as R + jX, where R is resistance and X is reactance, with j the square root of −1.
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the world > matter > physics > electromagnetic radiation > electricity > resistance > [noun] > reactance
reactance1893
inductive reactance1911
1893 Trans. Amer. Inst. Electr. Engineers 10 413 The term ‘impedance’ is suggested for the denominator..and for the quantity enclosed between the brackets, the term ‘reactance’ is proposed.
1920 Whittaker's Electr. Engineer's Pocket-bk. (ed. 4) 521 Should the speed be increased above synchronism, the reactance attains a negative value.
1940 Amateur Radio Handbk. (ed. 2) i. 10/2 The reactance of an inductance decreases as the frequency decreases, which is the opposite effect to that of a condenser.
1987 E. H. J. Pallett Aircraft Electr. Syst. (ed. 3) 203/1 Changes in frequency will change the ohmic values of reactance.
1997 Computer Music Jrnl. Summer 70/2 An antenna external to the Theremin chassis is connected to an ‘LC’ tank oscillator, with frequency determined by the reactance of a network composed of an inductance (L ) and capacitance (C).
b. = reactor n. 3.
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the world > matter > physics > electromagnetic radiation > electricity > resistance > [noun] > reactance > equipment providing
reactance1911
reactor1915
saturable reactor1929
1911 Gen. Electric Rev. 14 405/1 Reactances are now built and installed in synchronous machine circuits, for voltage regulation.
1947 R. Lee Electronic Transformers & Circuits vi. 150 To avoid introducing losses and attenuation in the transmission bands, reactances as nearly pure as practicable are used in the elements of a wave filter.
2006 D. Reimert Protective Relaying for Power Generation Syst. 144 The grounding reactance must limit the ground fault current below that of a three-phase fault.
2. Mechanics and Acoustics. The imaginary component of a mechanical or acoustic impedance (impedance n. 2), producing a phase difference between a driving force and the resulting motion but no dissipation of energy.
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the world > matter > physics > science of sound > sound-waves > [noun] > impedance > imaginary component of
reactance1915
the world > matter > physics > mechanics > force > [noun] > active mechanical force > any of properties representing > specific > imaginary component of
reactance1915
1915 Proc. Amer. Philos. Soc. 54 136 ‘Mechanical reactance’ of vibrating diaphragm (by analogy to alternating-current theory).
1932 W. West Acoustical Engin. iv. 54 The impedance comprises a resistance component, which depends on the rate of absorption of sound by the walls of the cavity..and an elastic reactance, in parallel, which depends on the volume of the cavity.
1968 H. J. Pain Physics of Vibrations & Waves ii. 38 Mass, like inductance, produces a positive reactance, and the stiffness behaves in exactly the same way as the capacitance.
2002 Proc. National Acad. Sci. U.S.A. 99 13206/2 The low-frequency cochlear reactance..is at least as important as the elastic reactance of the middle-ear cavity in attenuating pressure magnitude as a function of decreasing frequency.
3. Psychology. A response of resistance aroused in a person who feels his or her freedom of choice is threatened or impeded.
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the mind > mental capacity > psychology > experimental psychology > stimulus-response > response > [noun] > negative
reactance1966
1966 J. W. Brehm Theory of Psychol. Reactance i. 2 Since this hypothetical motivational state is in response to the reduction (or threatened reduction) of one's potential for acting, and conceptually may be considered a counterforce, it will be called ‘psychological reactance’.
1970 Jrnl. Personality & Social Psychol. 14 18 If the communication arouses reactance, the individual will tend to reject its position in order to demonstrate his freedom to decide for himself.
1995 C. K. Atkin in S. E. Martin & P. D. Mail Effects Mass Media on Use & Abuse Alcohol 41 Massive saturation..could..undermine the effect by generating psychological reactance..toward the messages.
2001 Polit. Psychol. 22 313 When people are aware of an experimental manipulation, they can show reactance or resistance.
Compounds
C1. Designating a coil or other component which provides reactance in an electrical circuit.
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1921 Wireless World 9 187/1 Reactance coils are used in conjunction with valve sets.
1955 Amer. Jrnl. Psychol. 68 306 To modulate the frequency of the primary signal, a reactance tube..is connected in parallel with the tuned (tank) circuit of the master oscillator.
2000 J. C. Rawlins Basic AC Circuits (ed. 2) x. 352/1 The circuit analysis methods of the resistance-capacitive reactance circuits and resistance-inductive reactance circuits are similar.
C2. Psychology. Of, relating to, or designating reactance (see sense 3), as reactance response, reactance theory, etc.
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1968 Amer. Jrnl. Psychol. 81 134 Many gaps still exist concerning our understanding of reactance theory.
1976 J. T. Tedeschi & S. Lindskold Social Psychol. viii. 361/1 Reactance studies in which subjects are told they are being evaluated for leadership.
1988 M. S. Taylor in R. J. Patti et al. Managing for Service Effectiveness in Social Welfare Organiz. 197 The adoption of a new feedback system that regularly reports back data on client satisfaction..might cause a reactance response [in employees].
2000 Jrnl. Marriage & Family 62 390 Reactance theory posits that if individuals are pressured to perform a particular behavior that they would have performed voluntarily, they will perceive that their freedom of choice is restricted or threatened, and they will try to restore their freedom by acting in the opposite direction.
Derivatives
reˈactance-like adj.
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1976 J. T. Tedeschi & S. Lindskold Social Psychol. viii. 360/1 Numerous experiments have shown reactance-like effects in the laboratory.
2004 J. M. Quinn & W. Wood in E. S. Knowles & J. A. Linn Resistance & Persuasion x. 200 This warning-induced resistance did not appear to emerge from a reactance-like desire to reestablish freedom to hold existing attitudes.
This entry has been updated (OED Third Edition, December 2008; most recently modified version published online March 2022).
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n.1893