What device is used to introduce inductance into a circuit?

What device is used to introduce inductance into a circuit?

• A. Capacitor
• B. Resistor
• C. Inductor
• D. Transformer

Answer: (C)

Inductance is provided by a device whose main job is to store energy in a magnetic field and oppose changes in current. That device is an inductor, typically a coil of wire that may have a magnetic core. Its inductance L determines how strongly it resists changes in current, and in AC circuits it presents inductive reactance X_L = ωL, shaping signals by slowing changes in current. The voltage across an inductor is proportional to the rate of change of current (V = L di/dt), which is why it’s used to introduce inductance into a circuit. A capacitor stores energy in an electric field and presents capacitive reactance, not inductance. A resistor dissipates energy as heat and doesn’t store energy. A transformer uses mutual inductance between windings to transfer energy, but the standard device to introduce a specific inductance into a circuit is the inductor.

Inductance is provided by a device whose main job is to store energy in a magnetic field and oppose changes in current. That device is an inductor, typically a coil of wire that may have a magnetic core. Its inductance L determines how strongly it resists changes in current, and in AC circuits it presents inductive reactance X_L = ωL, shaping signals by slowing changes in current. The voltage across an inductor is proportional to the rate of change of current (V = L di/dt), which is why it’s used to introduce inductance into a circuit. A capacitor stores energy in an electric field and presents capacitive reactance, not inductance. A resistor dissipates energy as heat and doesn’t store energy. A transformer uses mutual inductance between windings to transfer energy, but the standard device to introduce a specific inductance into a circuit is the inductor.