Definition
An alternating-current (AC) circuit whose dominant opposition to current flow is inductive reactance, produced by one or more coils (inductors). In such a circuit, the current lags the voltage in phase, and energy is alternately stored in and released from the magnetic field surrounding the coils.
Plain English
An AC circuit that contains coils. The coils resist changes in current by building up a magnetic field, which causes the current to rise and fall slightly behind the voltage.
Context Anchor
Seen in aircraft electrical-system study and maintenance, especially with relays, solenoids, motors, generators, and ignition coils.
Derivation
From Latin 'inducere', meaning 'to lead in' or 'bring on'. A coil 'leads in' or induces a magnetic field as current flows through it, and that field in turn induces a voltage that opposes changes in the current. The name reflects this back-and-forth induction between current and magnetic field.
Why Pilots Care
Inductive circuits can produce high-voltage spikes when current is suddenly interrupted, potentially damaging avionics or causing arcing if not properly suppressed.
Grounding Statement
When current starts or stops in a coil, the magnetic field grows or collapses and pushes back against the change.
Intuition Check
Do not read “inductive” as just “causing something” in a general way. In this context, it means the circuit’s magnetic field affects how the current changes.
Example Sentence 1
Because the aircraft's AC bus feeds several motors and transformers, it behaves largely as an inductive circuit, with current lagging voltage.
Example Sentence 2
Voltage spikes from the inductive circuit were suppressed with diodes to protect the aircraft's sensitive electronic instruments.