*Question G7A02:
Which of the following components are used in a power supply filter network?*  

*Correct Answer is  C: Capacitors and inductors*  

### AI Response: (may contain errors)  

To understand the components used in a power supply filter network, let's analyze the correct answer and the other choices.

### Correct Answer: C: Capacitors and inductors

- **Capacitors** are used in filter networks to smooth out voltage fluctuations by storing and releasing energy. They charge up when the voltage increases and discharge when it decreases, effectively reducing ripple voltage.
  
- **Inductors** are also used to filter out high-frequency noise. They resist changes in current, which helps maintain a steady output voltage.

### Why the Other Choices are Incorrect:

- **A: Diodes**  
  - While diodes are essential in rectifying AC to DC (converting alternating current to direct current), they are not primarily used in the filtering process itself. Their main role is in the conversion stage, not in filtering.

- **B: Transformers and transducers**  
  - Transformers are used to step up or step down voltage levels and are not part of the filtering process. Transducers convert one form of energy to another (e.g., sound to electrical), but they do not play a role in filtering power supply outputs.

- **D: All these choices are correct**  
  - This option is incorrect because not all the components listed (diodes, transformers, transducers) are used in the filtering process. Only capacitors and inductors are specifically used for filtering.

### Useful Formulas or Rules of Thumb:

- The effectiveness of a filter can often be evaluated using the formula for the cutoff frequency, which is important in designing filters:

$$
f_c = \frac{1}{2 \pi R C}
$$

where:
- $f_c$ = cutoff frequency in hertz
- $R$ = resistance in ohms
- $C$ = capacitance in farads

- A common rule of thumb is that larger capacitors will provide better smoothing of the output voltage, while inductors will help reduce high-frequency noise.

In summary, for a power supply filter network, capacitors and inductors are the key components used to ensure a stable and clean DC output.