where should a voltmeter that used to determine the potential diference across the circuit, locate in a parallel circuit?

The voltmeter should be in parallel with the circuit.

To determine the potential difference across a circuit, a voltmeter should be connected in parallel with the circuit. Here's how you can do it:

1. First, make sure the circuit is turned off and disconnected from any power source.
2. Identify the two points in the circuit where you want to measure the potential difference. These points might be across a specific component or across the entire circuit.
3. Connect the positive terminal of the voltmeter to one of the points where you want to measure the potential difference.
4. Connect the negative terminal of the voltmeter to the other point where you want to measure the potential difference.
5. Ensure that the voltmeter is set to measure the desired range of potential difference.
6. Once everything is connected correctly, you can turn on the circuit and observe the reading on the voltmeter. It will give you the potential difference across the selected points in the circuit.

Remember, connecting the voltmeter in parallel ensures that it directly measures the potential difference across the points without affecting the circuit's current flow.