*Question T6A06:
What type of electrical component stores energy in a magnetic field?*  

*Correct Answer is  C: Inductor*  

### AI Response: (may contain errors)  

The correct answer is **C: Inductor**.

### Explanation of the Correct Answer:
- An **inductor** is a passive electrical component that stores energy in a magnetic field when electric current flows through it. The energy stored can be calculated using the formula:
  
  $$E = \frac{1}{2} L I^2$$

  where:
  - $E$ = energy stored in joules
  - $L$ = inductance in henries
  - $I$ = current in amperes

### Why the Other Choices are Incorrect:
- **A: Varistor**
  - A varistor is a voltage-dependent resistor that protects circuits from voltage spikes. It does not store energy in a magnetic field.

- **B: Capacitor**
  - A capacitor stores energy in an electric field, not a magnetic field. The energy stored in a capacitor can be calculated using:
  
  $$E = \frac{1}{2} C V^2$$

  where:
  - $C$ = capacitance in farads
  - $V$ = voltage across the capacitor in volts

- **D: Diode**
  - A diode is a semiconductor device that allows current to flow in one direction only. It does not store energy in a magnetic field.

### Summary:
- Inductors are the components that store energy in a magnetic field, while capacitors store energy in an electric field, varistors protect against voltage spikes, and diodes control current direction. Understanding these differences is crucial for the Extra Class exam.