*Question G7C14:
The bandwidth of a band-pass filter is measured between what two frequencies?*  

*Correct Answer is  A: Upper and lower half-power*  

### AI Response: (may contain errors)  

The correct answer to the question about the bandwidth of a band-pass filter is:

**Upper and lower half-power**

### Explanation of the Correct Answer:
- The bandwidth of a band-pass filter is defined as the range of frequencies between the upper and lower half-power points. 
- The half-power point is where the output power drops to half of its maximum value, which corresponds to a decrease of 3 dB in power. 
- This is a standard way to define bandwidth in filters, as it indicates the frequencies over which the filter effectively passes signals.

### Why the Other Choices are Incorrect:
- **B: Cutoff and rolloff**
  - The term "cutoff" typically refers to the frequency at which the filter begins to attenuate signals, but "rolloff" describes the rate at which the filter attenuates signals beyond the cutoff frequency. These terms do not specifically define the bandwidth of a band-pass filter.

- **C: Pole and zero**
  - Poles and zeros are concepts from filter design that refer to the locations in the s-plane (complex frequency domain) that determine the filter's response. While they are important for understanding filter behavior, they do not directly define the bandwidth.

- **D: Image and harmonic**
  - The image frequency is a concept related to mixing and modulation, while harmonics refer to integer multiples of a fundamental frequency. Neither of these terms relates to the definition of bandwidth for a band-pass filter.

### Useful Formulas or Rules of Thumb:
- The bandwidth ($BW$) can be calculated as:
$$
BW = f_{upper} - f_{lower}
$$
where:
- $f_{upper}$ = upper half-power frequency
- $f_{lower}$ = lower half-power frequency

This formula helps you understand how to quantify the bandwidth of a band-pass filter based on its half-power points.