Electric Circuits - Mission EC1 Detailed Help

A simple circuit containing a battery and a light bulb is shown below. The current through the battery is ___.


 
When the requirements of an electric circuit are met, charge begins to flow through the battery, the wires and the bulb. Charges (electrons) everywhere begin to move once the final circuit connection is made. The charges march along together, everywhere at the same rate. Their marching begins immediately in response to the establishment of the circuit. There is no place in the circuit where charge carriers (electrons) become consumed or used up. The charge carriers do not disintegrate, disappear or otherwise become removed from the circuit. And there is no place in the circuit where charge carriers begin to pile up or accumulate. The rate at which charge enters the wires on one end of the circuit is the same as the rate at which charge exits the wires on the other end. Current - the rate of charge flow - is everywhere the same. Charge flow is like the movement of soldiers marching in step together, everywhere at the same rate. 


 
It is a common belief among Physics students that something is consumed in an electric circuit. The commonly held incorrect idea is that charge or current is used up in an electric circuit. Such students might believe that the current at the beginning of a circuit is much greater than the current at the end of the circuit. But don't be fooled! Charge is not consumed and the current is everywhere the same. Charge simply moves through the circuit from a high energy location toward the low energy location, everywhere at the same rate.
 
On the other hand, one could argue that the electrical energy possessed by the moving charges is consumed. Though a more accurate way of expressing it is to say that electrical energy is transformed into sound energy or light energy or mechanical energy. But in saying that energy is consumed or transformed is not to mean that the charge becomes somehow used up or consumed.