Question

When you add an identical additional battery in parallel, how does it change the potential difference across the circuit?

Answer 1

Adding an identical additional battery in parallel will not change the potential difference across the circuit. The potential difference across a circuit is determined by the voltage of the individual batteries or power sources in the circuit, and adding another identical battery in parallel will not change the total voltage of the circuit. The potential difference will remain the same, regardless of the number of batteries added in parallel.