Which device allows current to flow by closing the circuit?

Which device allows current to flow by closing the circuit?

• A. Battery
• B. Buzzer
• C. Capacitor
• D. Closed switch

Answer: (D)

When current can move, the circuit is complete. A closed switch acts like a gate that completes the path from the power source back to itself, letting electrons flow through the wiring and any loads in between. With the switch open, the path is broken and no current can circulate, even if a battery is present. The battery provides the energy to push the current, but it requires a closed circuit to do so. A buzzer is simply a load that uses the current to make sound, not something that creates the path. A capacitor can allow a brief surge of current while charging or discharging, but it doesn’t continuously guarantee flow in a basic on/off scenario. So, the device that enables current to flow by closing the circuit is the closed switch.

When current can move, the circuit is complete. A closed switch acts like a gate that completes the path from the power source back to itself, letting electrons flow through the wiring and any loads in between. With the switch open, the path is broken and no current can circulate, even if a battery is present. The battery provides the energy to push the current, but it requires a closed circuit to do so. A buzzer is simply a load that uses the current to make sound, not something that creates the path. A capacitor can allow a brief surge of current while charging or discharging, but it doesn’t continuously guarantee flow in a basic on/off scenario. So, the device that enables current to flow by closing the circuit is the closed switch.