capacitive reactance: meaning, definition, pronunciation and examples
Very LowTechnical / Academic
Quick answer
What does “capacitive reactance” mean?
The opposition that a capacitor offers to alternating current (AC), measured in ohms, which decreases as frequency increases.
Audio
Pronunciation
Definition
Meaning and Definition
The opposition that a capacitor offers to alternating current (AC), measured in ohms, which decreases as frequency increases.
A key parameter in AC circuit analysis representing the inertial-like lag between voltage and current in a purely capacitive circuit, crucial for designing filters, timing circuits, and impedance matching networks.
Dialectal Variation
British vs American Usage
Differences
No significant differences in usage or spelling. The term is standardized in international engineering.
Connotations
Purely technical, with no regional connotations.
Frequency
Equally rare outside specific engineering contexts in both regions.
Grammar
How to Use “capacitive reactance” in a Sentence
The capacitive reactance (of [Component]) is [Value].[Component] presents a capacitive reactance of [Value].Vocabulary
Collocations
Examples
Examples of “capacitive reactance” in a Sentence
verb
British English
- The circuit is designed to capacitive reactance dominate at low frequencies.
- Engineers must account for how the component will capacitive reactance the signal.
American English
- The filter uses a capacitor to capacitive reactance the 60 Hz hum.
- You need to capacitive reactance the input for proper phase shift.
adverb
British English
- The current lags capacitive reactance.
- Not applicable.
American English
- The voltage leads capacitive reactance.
- Not applicable.
adjective
British English
- The capacitive reactance effect was pronounced.
- We measured the capacitive reactance component.
American English
- The capacitive reactance value is too high.
- A capacitive reactance network was added.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in electrical engineering, physics, and electronics textbooks and papers.
Everyday
Never used.
Technical
Core term in AC circuit theory, electronics design, and signal processing.
Vocabulary
Synonyms of “capacitive reactance”
Strong
Neutral
Weak
Vocabulary
Antonyms of “capacitive reactance”
Watch out
Common Mistakes When Using “capacitive reactance”
- Pronouncing 'reactance' as 're-act-ance' with equal stress on all syllables (correct: re-AC-tance).
- Using 'capacitive resistance' which is incorrect as it does not dissipate power.
- Forgetting it is frequency-dependent.
FAQ
Frequently Asked Questions
No. Resistance (R) dissipates energy as heat. Capacitive reactance (Xc) stores energy in an electric field and releases it, causing a phase shift without average power dissipation.
The unit is the ohm (Ω), the same as for resistance, but it represents a different kind of opposition to current.
Because at higher frequencies, the capacitor has less time to charge and discharge per cycle, offering less opposition to the changing current.
In physics and engineering calculations, capacitive reactance is often assigned a negative imaginary value (-jXc) to distinguish it from positive inductive reactance (+jXl) when working with complex impedance.
The opposition that a capacitor offers to alternating current (AC), measured in ohms, which decreases as frequency increases.
Capacitive reactance is usually technical / academic in register.
Capacitive reactance: in British English it is pronounced /kəˌpæs.ɪ.tɪv riˈæk.təns/, and in American English it is pronounced /kəˌpæs.ə.ṭɪv riˈæk.təns/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “Not applicable.”
Learning
Memory Aids
Mnemonic
Think CAPACitive reACTANCE: a CAPACitor ACTs against AC flow, and the ANCE is its resist-ANCE.
Conceptual Metaphor
A spring in a mechanical system: it doesn't dissipate energy like friction (resistance) but stores and releases it, opposing changes in force (voltage/current).
Practice
Quiz
What happens to capacitive reactance (Xc) if the frequency (f) is doubled?