According to Kirchhoff's Current Law, the sum of currents in the branches equals:

• A. The current leaving the power supply
• B. The voltage across the supply
• C. The current in the main conductor
• D. The resistance of the circuit

Answer: (A)

The idea being tested is that current is conserved at a node. At a junction where a power source feeds multiple branches, the currents flowing into the node must equal the currents flowing out. Therefore, the sum of the branch currents equals the current leaving the power supply.

Voltage across the supply isn’t what Kirchhoff’s Current Law uses here—it’s about potential difference, not current balance. The current in the main conductor alone isn’t the total of all branch currents. And resistance describes how voltage and current relate, not the conservation of current at a node. So the best description is that the currents in the branches add up to the current leaving the source.