When AC current flows into a coil, there is additional opposition to current flow caused by __________.

When AC current flows into a coil, there is additional opposition to current flow caused by __________.

• A. Capacitive Reactance
• B. Ohmic Resistance
• C. Magnetic Flux
• D. Inductive Reactance

Answer: (D)

A coil in an AC circuit resists changes in current because the changing magnetic field inside the coil induces a voltage that opposes the very change in current. This reactive opposition, called inductive reactance, grows with both the coil’s inductance and the frequency of the AC signal (X_L = 2πfL). In other words, higher frequency makes the coil push back more against the changing current. Capacitive reactance would come from a capacitor, not a coil. Ohmic resistance is the regular, real loss in the wire and exists regardless of AC or DC, but the “additional opposition” described here specifically refers to the inductive effect. Magnetic flux is what changes to create that opposing EMF, not the opposition itself.

A coil in an AC circuit resists changes in current because the changing magnetic field inside the coil induces a voltage that opposes the very change in current. This reactive opposition, called inductive reactance, grows with both the coil’s inductance and the frequency of the AC signal (X_L = 2πfL). In other words, higher frequency makes the coil push back more against the changing current.

Capacitive reactance would come from a capacitor, not a coil. Ohmic resistance is the regular, real loss in the wire and exists regardless of AC or DC, but the “additional opposition” described here specifically refers to the inductive effect. Magnetic flux is what changes to create that opposing EMF, not the opposition itself.