Inductance is typically demonstrated by which component, and what does it do?

• A. A capacitor; stores charge
• B. A coil; resists changes in current by generating induced EMF
• C. A resistor; dissipates energy as heat
• D. A diode; rectifies current

Answer: (B)

Inductance is about how a component resists changes in current by generating a voltage that tends to oppose the change. A wound conductor, or coil, is the typical demonstration of this behavior. When current through the coil tries to rise or fall, the changing magnetic field induces an electromotive force in the coil itself that opposes that change, per Lenz’s law. This relationship is described by v = L di/dt, where L is the inductance. In practical terms, the coil stores energy in its magnetic field and resists instantaneous current changes, which is why inductors are used for timing, filtering, and smoothing in circuits. The other components mentioned—capacitors store energy as separated charges, resistors convert electrical energy to heat, and diodes rectify current—do not primarily illustrate inductance.