If a circuit is open, which of the following is true?

If a circuit is open, which of the following is true?

• A. Current Flows
• B. Voltage Is Zero
• C. No Current Flows
• D. Short Occurs

Answer: (C)

An open circuit has a break in the conducting path, so electrons can’t complete a loop. Current needs a closed path to flow, and without it the current is zero, even if a voltage source is connected. The voltage across the open gap can be nonzero—up to the source voltage—because there’s nothing present to drive current through. A short circuit is the opposite situation: a closed path with very low resistance, which allows a large current to flow. So the true statement is that no current flows in an open circuit.

An open circuit has a break in the conducting path, so electrons can’t complete a loop. Current needs a closed path to flow, and without it the current is zero, even if a voltage source is connected. The voltage across the open gap can be nonzero—up to the source voltage—because there’s nothing present to drive current through. A short circuit is the opposite situation: a closed path with very low resistance, which allows a large current to flow. So the true statement is that no current flows in an open circuit.