*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 bandwidth of a band-pass filter is defined as the range of frequencies that the filter allows to pass through with minimal attenuation. This is measured between two specific frequencies:

1. **Correct Answer: Upper and lower half-power**  
   - The bandwidth is measured between the upper and lower half-power points, also known as the -3 dB points. These are the frequencies at which the power output of the filter is half of the maximum power output.  
   - The half-power points are important because they define the effective range of frequencies that the filter can pass with minimal loss.  
   - The bandwidth ($BW$) can be calculated as:  
     $$BW = f_{\text{upper}} - f_{\text{lower}}$$  
     where $f_{\text{upper}}$ and $f_{\text{lower}}$ are the upper and lower half-power frequencies, respectively.

2. **Why the other choices are incorrect:**
   - **Cutoff and rolloff**: These terms are not specific points used to define bandwidth. "Cutoff" can sometimes refer to the -3 dB point, but "rolloff" describes how quickly the filter attenuates frequencies outside the passband.
   - **Pole and zero**: These are terms from filter design theory related to the transfer function of the filter, not directly related to measuring bandwidth.
   - **Image and harmonic**: These terms relate to unwanted frequencies in radio systems. "Image" refers to frequencies that can cause interference in superheterodyne receivers, and "harmonic" refers to multiples of a fundamental frequency. Neither is used to define the bandwidth of a filter.

Understanding these concepts will help you identify the correct points for measuring the bandwidth of a band-pass filter.