SOLUTION

Energy is required to move a charge from one point to another. Potential difference in electrical terminology is known as voltage, and is denoted by either V or v. Voltage is expressed in terms of energy (W) per unit charge (Q), i.e.

V = W/Q or v = dw/dq

Where

dw = small change in energy

dq = small change in charge

The energy (W) is expressed in joule (]), the charge (Q) is expressed in coulomb (C), and the voltage (V) is expressed in volt (V). The unit of voltage is volt.

1 volt = 1 joule/coulomb