Multiple choice general knowledge

What is reactance?

  1. Opposition to the flow of direct current caused by resistance

  2. A property of ideal resistors in AC circuits

  3. Opposition to the flow of alternating current caused by capacitance or inductance

  4. A large spark produced at switch contacts when an inductor is deenergized

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Reactance is the opposition to the flow of alternating current caused specifically by capacitance or inductance in a circuit. It is a component of impedance and is measured in ohms. Capacitive reactance decreases with frequency, while inductive reactance increases with frequency. Option A is incorrect because reactance applies to AC, not DC. Option D describes an inductive spike, not reactance itself.