*Question G5C14:
Which of the following components should be added to an inductor to increase the inductance?*  

*Correct Answer is  D: An inductor in series*  

### AI Response: (may contain errors)  

To increase the inductance of an inductor, you should add another inductor in series. Here's why:

1. **Correct Answer: An inductor in series (D)**
   - When inductors are connected in series, their inductances add up. The total inductance $L_{\text{total}}$ is given by:
     $$L_{\text{total}} = L_1 + L_2 + \ldots + L_n$$
   - This is similar to how resistances add in series. By adding an inductor in series, you effectively increase the total inductance.

2. **Why the other choices are incorrect:**
   - **A capacitor in series (A):** 
     - Adding a capacitor in series does not increase inductance. Instead, it creates a resonant circuit, which can affect the impedance at certain frequencies but does not increase inductance.
   - **A capacitor in parallel (B):**
     - Similar to a series capacitor, a parallel capacitor forms a resonant circuit with the inductor, affecting the circuit's frequency response but not increasing inductance.
   - **An inductor in parallel (C):**
     - When inductors are connected in parallel, the total inductance decreases. The formula for total inductance in parallel is:
       $$\frac{1}{L_{\text{total}}} = \frac{1}{L_1} + \frac{1}{L_2} + \ldots + \frac{1}{L_n}$$
     - This is the opposite of what is needed to increase inductance.

By understanding these principles, you can see why adding an inductor in series is the correct choice to increase the total inductance.