By repeating steps 1 and 2, as needed, the circuit can be simplified to an equivalent series circuit. Simply add the equivalent resistances of the simplified equivalent series circuit to find the total resistance of the compound circuit. At this point the circuit has been simplified to an equivalent series circuit consisting of an equivalent resistance of 1.33 k W and a resistance of 3 k W . The energy available to move electrons is referred to as difference in potential, or voltage. Voltage is most often provided by a battery or generator.
Voltage represents the work involved in the transfer of electric charge from one point to another.
The higher the voltage, the more energy the current carries and the more work it can do. In electric applications, voltage is often converted to other forms of energy to do work, such as heating, lighting, or motion. As noted earlier, we often make use of resistance to convert electric energy to heat or light. The rate at which electricity does work or provides energy is referred to as electric power. The unit of electric power is the watt.