This mechanical system consists of a pump pushing water through a closed pipe. The pump is the mechanical counterpart of the battery. The pressure generated by the pump, that drives the water through the pipe, is like the voltage generated by the battery to drive the electrons through the circuit. The seashells plug up the pipe and constrict the flow of the water creating a pressure difference from one end to the other. In a similar manner the resistance in the electric circuit resists the flow of electricity and creates a voltage drop from one end to the other.
Energy is lost across the resistor and shows up as heat.
The power in the circuit is given by the product of the voltage and the current. The same power can be carried by a high voltage and a low current as is carried by a low voltage and a high current. The higher the current flow however, the more energy is lost through heating the wires when traversing the circuit. That's why high voltage and low current is used when transporting electrical energy along power lines. All Rights Reserved.