*Question E5A13:
What is an effect of increasing Q in a series resonant circuit?*  

*Correct Answer is  C: Internal voltages increase*  

### AI Response: (may contain errors)  

In a series resonant circuit, the quality factor (Q) is a measure of how underdamped the circuit is, which affects its bandwidth and peak response.

### Correct Answer: C - Internal voltages increase

- **Explanation**: 
  - As the Q factor increases, the circuit becomes more selective and has a narrower bandwidth. This means that at resonance, the voltage across the resonant components (like the inductor and capacitor) can become significantly higher than the input voltage. This phenomenon is due to the energy being stored and released in the reactive components, leading to higher internal voltages.

### Why the Other Choices are Incorrect:

- **A: Fewer components are needed for the same performance**  
  - This is incorrect because increasing Q does not reduce the number of components required. Instead, achieving a higher Q often involves using higher quality components (like inductors and capacitors) or additional tuning elements, which may increase complexity.

- **B: Parasitic effects are minimized**  
  - This is incorrect because increasing Q can actually make parasitic effects more pronounced. A higher Q means a narrower bandwidth, which can lead to greater sensitivity to parasitic capacitance and inductance, potentially degrading performance.

- **D: Phase shift can become uncontrolled**  
  - This is incorrect because while a high Q can lead to significant phase shifts at frequencies near resonance, it does not inherently make the phase shift "uncontrolled." The phase shift is predictable and can be calculated based on the circuit parameters.

### Useful Formulas and Rules of Thumb:

- The Q factor for a series resonant circuit can be defined as:

$$
Q = \frac{f_0}{\Delta f}
$$

where:
- $f_0$ = resonant frequency
- $\Delta f$ = bandwidth (the frequency range over which the circuit can operate effectively)

- A higher Q indicates a sharper peak in the frequency response, leading to higher voltages at resonance. 

Understanding these concepts will help you grasp the implications of Q in resonant circuits and prepare you for related questions on the exam.