How is total current calculated in a parallel circuit?

In a parallel circuit, the total current is indeed calculated by summing the individual currents flowing through each parallel branch. This principle is based on Kirchhoff's Current Law, which states that the total current entering a junction must equal the total current leaving that junction. Therefore, you add the currents from all the branches to get the total current.

Each branch of the parallel circuit can have different resistances and thereby draw different amounts of current. By calculating the total current as the sum of the currents from each branch, you ensure an accurate representation of the total current in the circuit. This method is fundamental for understanding current distribution in parallel circuits and is crucial when designing or troubleshooting fire alarm systems and other electrical installations.

The other calculations provided do not fit the requirements for parallel circuits: multiplying currents does not yield a correct result, and the formulas involving voltage and resistance apply to Ohm’s Law, which is not directly relevant for calculating total current in a parallel circuit.