What are inductors used for?

What are inductors used for?

• A. To add resistance to
• B. To store energy in the electric field
• C. To convert DC to AC
• D. To dissipate power as heat

Answer: (B)

Inductors are energy storage elements that store energy in the magnetic field created by current flowing through a coil. As current builds, a magnetic field forms around the winding and holds energy equal to (1/2)LI^2. This ability to store energy and oppose changes in current makes inductors useful for smoothing currents, filtering signals, and helping with energy transfer in power converters. The other functions described by the distractors—adding resistance, converting DC to AC, or dissipating power as heat—are not what inductors primarily do. A helpful contrast is that capacitors store energy in the electric field, while inductors store energy in the magnetic field.

Inductors are energy storage elements that store energy in the magnetic field created by current flowing through a coil. As current builds, a magnetic field forms around the winding and holds energy equal to (1/2)LI^2. This ability to store energy and oppose changes in current makes inductors useful for smoothing currents, filtering signals, and helping with energy transfer in power converters. The other functions described by the distractors—adding resistance, converting DC to AC, or dissipating power as heat—are not what inductors primarily do. A helpful contrast is that capacitors store energy in the electric field, while inductors store energy in the magnetic field.