American Society of Radiologic Technologist (ASRT) Practice Exam

For current to flow, voltage is a crucial component because it serves as the force that pushes the electrons through a circuit. Voltage can be understood as the electrical potential difference between two points. When there is a sufficient voltage, it creates an electric field that drives the flow of charge carriers (such as electrons) from the negative terminal to the positive terminal of a power source.

In a circuit, even if resistance is present—because ohmic materials will allow current to flow up to a certain limit—what ultimately initiates the flow is the voltage. Without voltage, there is no trigger for the electrons to move; hence, no current can be established.

Though resistance and other factors like capacitance may impact how much current flows, voltage remains the essential element that initiates the current flow in the first place.