Electronics quiz
Inductors quiz
Coils, magnetic fields, and why they fight a current that's changing.
18 questions in the app. A few of them, with their answers:
What is inductance measured in?
- Farads
- Henries ✓
- Ohms
- Webers
Answer Inductance is measured in henries (H), usually seen in practice as mH or µH.
What does an inductor fundamentally do?
- Stores energy as an electric field
- Stores energy as a magnetic field ✓
- Blocks all AC signals permanently
- Converts AC to DC by itself
Answer An inductor is a coil that stores energy as a magnetic field when current flows through it.
An inductor opposes:
- A constant DC current
- A change in current ✓
- A change in voltage
- Any current flow whatsoever
Answer V = L·di/dt: an inductor resists CHANGES in current. A steady DC current flows through it with only the coil's own resistance to limit it.
In an AC circuit, an inductor's impedance increases with:
- Lower frequency
- Higher frequency ✓
- Lower voltage
- Higher resistance
Answer Inductive reactance XL = 2πfL grows with frequency, so an inductor blocks high frequencies more than low ones - the opposite of a capacitor.
What is a common real-world form of an inductor?
- Two parallel metal plates
- A coil of wire, often wound around a core ✓
- A doped semiconductor junction
- A thin metal film on a ceramic body
Answer Winding wire into a coil (often around a ferrite or iron core) concentrates the magnetic field and is how most inductors are built.
