In a parallel circuit with multiple branches, how is the total current determined?

• A. The total current is the sum of currents through each branch.
• B. The current is the same through every branch.
• C. The current through each branch equals its resistance.
• D. The current is inversely proportional to voltage.

Answer: (A)

In parallel circuits, the current from the power source splits among the branches, and the total current is the sum of the currents through each branch. Each branch has the same voltage across it, so the current in a branch is I = V/R_branch. The overall current drawn from the source is I_total = I1 + I2 + … + In.

For example, with a 12 V supply and two branches having resistances of 4 Ω and 12 Ω, the branch currents are 12/4 = 3 A and 12/12 = 1 A, giving a total current of 4 A.

This is why the total current is the sum of the branch currents. The current is not the same in every branch (that would be true in a series circuit), and it isn’t determined by the branch resistance alone without considering the shared voltage.