Which statement is Kirchhoff's Voltage Law?

Which statement is Kirchhoff's Voltage Law?

• A. The algebraic sum of all voltage drops in any closed circuit is zero.
• B. The sum of currents around a loop equals zero.
• C. The product of current and resistance equals voltage.
• D. The voltage across a resistor decreases with time.

Answer: (A)

Kirchhoff's Voltage Law says that the algebraic sum of voltages around any closed loop is zero. This expresses energy conservation: as you traverse a loop, voltage rises and drops balance out, returning you to the same potential at the starting point. The statement that the algebraic sum of all voltage drops in any closed circuit is zero matches this idea, because it accounts for the signs of rises and drops so they cancel. The other options describe different principles: summing currents around a loop isn’t a standard law (Kirchhoff's Current Law applies at nodes, not loops); Ohm's law relates voltage to current and resistance for a single element, not a loop total; and a voltage across a resistor decreasing with time isn’t a general circuit-law statement and doesn’t describe the loop voltage balance KVL asserts.

Kirchhoff's Voltage Law says that the algebraic sum of voltages around any closed loop is zero. This expresses energy conservation: as you traverse a loop, voltage rises and drops balance out, returning you to the same potential at the starting point. The statement that the algebraic sum of all voltage drops in any closed circuit is zero matches this idea, because it accounts for the signs of rises and drops so they cancel. The other options describe different principles: summing currents around a loop isn’t a standard law (Kirchhoff's Current Law applies at nodes, not loops); Ohm's law relates voltage to current and resistance for a single element, not a loop total; and a voltage across a resistor decreasing with time isn’t a general circuit-law statement and doesn’t describe the loop voltage balance KVL asserts.