- Voltage is a measure of electrical potential, i.e. the ratio of energy per coulomb of charge. V=W/Q .
- A potential difference between two points in a circuit, means that the potential (or voltage) at one point is
higher than the other.
- The potential difference across a power supply, is due to an e.m.f. supplying energy, to raise
the potential of charged particles as they move through it.
- A voltage drop occurs across resistors, because they convert electrical energy to heat. This reduces the electrical potential of electrons flowing through it.
- True electron flow is from negative to positive, with the electrons at the negative terminal of a battery having a higher
- Conventional current flow refers to positive charge flowing from a higher potential, at the positive terminal, to a lower potential at the negative terminal.
(This is base on a historical misconception about the true nature of electrical current)