Which statement about a closed electric circuit is true?

Which statement about a closed electric circuit is true?

• A. A circuit without any voltage source can still have current.
• B. A battery always produces no current in a circuit.
• C. An open circuit permits current to flow.
• D. A closed path along which electrons can flow ensures current can move.

Answer: (D)

Current is the flow of electrons, and it only happens when there is a complete, conducting path from the power source, through any devices, and back to the source. A closed circuit provides that unbroken loop, so a voltage source can push electrons around and establish a steady current. If the loop is broken (an open circuit), the path isn’t complete, and electrons can’t keep moving, so no sustained current flows. A battery doesn’t always produce no current—it supplies the push—but that push only results in current when the circuit is closed. So the statement that a closed path along which electrons can flow ensures current can move captures the essential condition for current to occur.

Current is the flow of electrons, and it only happens when there is a complete, conducting path from the power source, through any devices, and back to the source. A closed circuit provides that unbroken loop, so a voltage source can push electrons around and establish a steady current. If the loop is broken (an open circuit), the path isn’t complete, and electrons can’t keep moving, so no sustained current flows. A battery doesn’t always produce no current—it supplies the push—but that push only results in current when the circuit is closed. So the statement that a closed path along which electrons can flow ensures current can move captures the essential condition for current to occur.