susceptance
C2 (Very Rare / Specialised)Formal Technical / Academic (Engineering, Physics)
Definition
Meaning
In electrical engineering, the imaginary component of admittance, representing the part of alternating current that is out of phase with voltage due to a purely reactive element (capacitance or inductance).
A technical measure of how readily a circuit or component allows alternating current to flow when the driving force is in quadrature (90° out of phase) with the current; more broadly, a symbolic representation of reactive current flow. It is the reciprocal of reactance.
Linguistics
Semantic Notes
Purely a technical term from AC circuit theory. Denotes a scalar quantity (symbol B) measured in Siemens (S). Always contrasted with 'conductance' (the real part of admittance). Does NOT relate to the general English word 'susceptibility' in meaning.
Dialectal Variation
British vs American Usage
Differences
No significant differences in meaning or usage. Spelling and terminology are identical.
Connotations
None beyond its precise technical definition.
Frequency
Equally rare and confined to identical technical contexts in both dialects.
Vocabulary
Collocations
Grammar
Valency Patterns
The susceptance [of a component] is...To calculate/derive/find the susceptanceSusceptance is defined as...Susceptance contributes to the total admittanceVocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “None”
Usage
Context Usage
Business
Virtually never used.
Academic
Exclusively used in advanced physics and electrical/electronic engineering textbooks, papers, and lectures on AC circuit analysis.
Everyday
Never used in everyday conversation.
Technical
The primary domain. Used in circuit design, power systems analysis, RF engineering, and impedance matching discussions.
Examples
By Part of Speech
verb
British English
- The circuit does not 'susceptance'; the term is a noun only.
American English
- The circuit does not 'susceptance'; the term is a noun only.
adverb
British English
- The current flowed susceptively? (Not standard usage).
American English
- The current flowed susceptively? (Not standard usage).
adjective
British English
- The susceptive component was analysed. (Note: 'susceptive' is related but distinct).
American English
- The susceptive properties were measured. (Note: 'susceptive' is related but distinct).
Examples
By CEFR Level
- This word is not used at A2 level.
- This word is not typically used at B1 level.
- In our physics class, we learned that admittance has two parts: conductance and something called susceptance.
- The engineer calculated the total admittance of the network by summing the conductance and the susceptance, the latter being negative for the inductive load.
Learning
Memory Aids
Mnemonic
Think: 'SUSCEPTANCE' starts like 'susceptible'. A circuit with high susceptance is highly *susceptible* to letting reactive current flow 90 degrees out of phase.
Conceptual Metaphor
In AC circuits, if conductance is like a clear, straight pipe for in-phase current, susceptance is like a side-chamber that stores and releases energy, causing a sloshing, out-of-phase flow.
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'восприимчивость' (susceptibility). The correct technical translation is 'реактивная проводимость' (reaktivnaya provodimost').
- It is a component of 'полная проводимость' (admittance), not 'сопротивление' (resistance).
Common Mistakes
- Mispronouncing it as /ˈsʌsəptəns/ (like 'suspect').
- Confusing it with 'susceptibility'.
- Using it outside of AC circuit contexts.
- Forgetting it is measured in Siemens, not Ohms.
Practice
Quiz
Susceptance is a measure primarily associated with which of the following?
FAQ
Frequently Asked Questions
No, they are reciprocals. Reactance (X) opposes alternating current, measured in Ohms. Susceptance (B) is the imaginary part of admittance (Y), which is how easily alternating current flows, and is measured in Siemens. B = -1/X for a pure reactive element.
Primarily when working with admittance directly, especially in parallel AC circuit analysis, power system studies (like load flow analysis), and RF/microwave engineering where admittance parameters (Y-parameters) are standard.
Yes. Capacitive susceptance is defined as positive, and inductive susceptance is negative. This sign convention indicates the phase relationship of the current relative to the voltage.
It is a highly specialised term from a niche area of electrical engineering. Most general discussions of circuits use the more familiar concepts of resistance and reactance, making 'impedance' more common than its reciprocal, 'admittance', of which susceptance is a part.