What is the formula used to calculate the total current in a parallel circuit?

In a parallel circuit, the key characteristic is that the voltage across each branch is the same, while the total current is the sum of the currents through each individual branch. This leads to the correct formula for calculating the total current in a parallel circuit being I_total = I1 + I2 + I3.

This equation reflects the principle of conservation of electric charge, stating that the total current entering a junction must equal the total current leaving. Each individual current (I1, I2, I3, etc.) represents the current flowing through each component connected in parallel. Thus, to obtain the total current flowing from the source, you simply add together the currents from each branch.

The other options provided do not directly represent how to calculate the total current in a parallel circuit. While some of them may pertain to current in other contexts, such as Ohm's Law (V = IR), they do not reflect the specific scenario of parallel circuits.