why does the light bulb in a circuit turn on when the switch is closed? responses the switch changes the circuit from series to parallel. the switch changes the circuit from series to parallel. the switch changes the direction of the flow of electrons. the switch changes the direction of the flow of electrons. the switch absorbs the electrical energy. the switch absorbs the electrical energy. closing the switch completes the circuit, making it a closed circuit. closing the switch completes the circuit, making it a closed circuit.