Answer:
The resistance of the clock circuit.
Explanation:
In electricity, the potential difference or voltage is the drive force. It is known as the electromotive force in a battery or generator. The potential difference is the difference in the higher terminal and the lower terminal of the circuit. The potential difference forces electrons to move in an orderly fashion, from the higher potential to the lower potential; this flowing electrons is what is called the current of the circuit. When the electrons flow, they meet a certain amount of resistance. This resistance is unique to the material of the circuitry, and does not change in a circuit. The value of the resistance of the circuit remains the same, even when the potential difference of the electrical energy source is depleted, and current stops to flow.