*Question E4A09:
Which of the following is good practice when using an oscilloscope probe?*  

*Correct Answer is  A: Minimize the length of the probe's ground connection*  

### AI Response: (may contain errors)  

When using an oscilloscope probe, it's important to minimize the length of the probe's ground connection. Here's why:

1. **Correct Answer: Minimize the length of the probe's ground connection**  
   - **Reason**: A shorter ground connection reduces the inductance and potential for noise pickup. This helps maintain signal integrity and provides more accurate measurements. Long ground leads can act like antennas, picking up unwanted signals and distorting the measurement.

2. **Why the other choices are incorrect**:
   - **Choice B: Never use a high-impedance probe to measure a low-impedance circuit**  
     - **Reason**: High-impedance probes are often used to measure low-impedance circuits because they minimize the loading effect on the circuit. Using a high-impedance probe is generally good practice as it prevents the probe from significantly affecting the circuit's operation.
   
   - **Choice C: Never use a DC-coupled probe to measure an AC circuit**  
     - **Reason**: DC-coupled probes can be used to measure AC signals. In fact, using a DC-coupled probe allows you to see both the AC and DC components of a signal. The choice of coupling (AC or DC) depends on whether you need to observe the DC offset in addition to the AC waveform.

3. **Useful Rule of Thumb**:
   - When using an oscilloscope, always aim to minimize any potential sources of error or interference, such as long ground leads, to ensure accurate and reliable measurements.