Which component is used to control whether the circuit is complete by opening or closing the path?

Which component is used to control whether the circuit is complete by opening or closing the path?

• A. Battery
• B. Cell
• C. Resistor
• D. Switch

Answer: (D)

The ability to control whether a circuit is complete by opening or closing the path comes from a switch. In a circuit, current only flows if there is a continuous loop from the power source, through conductors and any loads, back to the source. A switch sits in that loop and can connect or disconnect it. When the switch is closed, the contacts touch and the loop is complete, so current flows. When the switch is opened, the contacts separate and the loop is broken, so current stops. The battery (or other power source) provides the voltage, and a resistor acts as a load that limits current, but neither alone decides whether the path is complete. The switch is the component that directly controls that on/off state.

The ability to control whether a circuit is complete by opening or closing the path comes from a switch. In a circuit, current only flows if there is a continuous loop from the power source, through conductors and any loads, back to the source. A switch sits in that loop and can connect or disconnect it. When the switch is closed, the contacts touch and the loop is complete, so current flows. When the switch is opened, the contacts separate and the loop is broken, so current stops. The battery (or other power source) provides the voltage, and a resistor acts as a load that limits current, but neither alone decides whether the path is complete. The switch is the component that directly controls that on/off state.