In a parallel circuit, the voltage across each branch is the same.

• A. The current is the same in all branches
• B. The resistance is the same in all branches
• C. The voltage across each branch is the same
• D. The power in each branch is the same

Answer: (C)

In a parallel circuit, the voltage across each branch is the same because every branch is connected directly between the same two nodes of the circuit, so the same potential difference from the source appears across every branch. This means the current in each branch depends on that branch’s resistance, via I = V / R_branch, so currents can vary even though the voltage is identical. The resistances in the branches do not have to be the same, which is why currents differ. Power in each branch is P = V^2 / R_branch (or P = I^2 R_branch); with the same voltage across all branches, different resistances lead to different powers, so the branches won’t all dissipate the same amount of power. For example, with a 12 V source, a 3-ohm branch would draw 4 A and dissipate 48 W, while a 6-ohm branch would draw 2 A and dissipate 24 W.