*Question T7D01:
Which instrument would you use to measure electric potential?*  

*Correct Answer is  B: A voltmeter*  

### AI Response: (may contain errors)  

To measure electric potential, the correct instrument to use is a voltmeter. 

### Explanation of the Correct Answer:
- **Voltmeter**: This instrument is specifically designed to measure the electric potential difference (voltage) between two points in an electrical circuit. It is connected in parallel with the component across which the voltage is to be measured.

### Why the Other Choices are Incorrect:
- **Ammeter**: This device measures electric current (in amperes) flowing through a circuit. It is connected in series with the circuit, not parallel, and cannot measure voltage.
  
- **Wavemeter**: A wavemeter is used to measure the frequency of radio waves or the wavelength of signals. It does not measure voltage or electric potential.
  
- **Ohmmeter**: This instrument measures resistance (in ohms) in a circuit. It is used to determine how much opposition there is to the flow of current, not to measure voltage.

### Summary:
- **Correct Instrument**: Voltmeter (measures voltage)
- **Incorrect Instruments**: Ammeter (measures current), Wavemeter (measures frequency), Ohmmeter (measures resistance)

Understanding the specific functions of these instruments is crucial for effective troubleshooting and measurement in electrical and radio systems.