The Basic lessons · Basic electronics and theory · B-005-010

Reacting to Change: How Inductors and Capacitors Behave

Learn why inductors block high frequencies while capacitors block low ones, and how these properties shape radio circuits. Understand the difference between resistance, reactance, and impedance to predict circuit behaviour.

This lesson is part of SignalPrep Pro. The subsection's 11 exam questions are free to practise: practise B-005-010.

What this subsection asks

• How does an inductor react to AC?
• How does a capacitor react to AC?
• The reactance of capacitors increases as:
• What is the term for the opposition to alternating current caused by the combined effect of reactance and resistance?
• What term equals the ratio of AC voltage to AC current in a system or circuit?
• What circuit parameter change causes an inductor's reactance to increase?
• What property allows a coil wound on a ferrite core to mitigate the effects of an offending radio signal?
• What property allows a bypass capacitor in an audio circuit to divert an interfering RF signal?
• What property allows an RF bypass capacitor to have little effect on an audio circuit?
• What property allows an RF choke coil to have little effect on signals meant to flow through the coil?
• In general, the reactance of inductors increases with: