A resistor determines the amount of energy capable of passing through, because the resistors material restricts the movement of electrons in the material. The resistance, R of a material is defined as the ratio V/I, where V is the potential difference across the...
An electric current is a flow of charge. When a torch is switched on electrons flow through the torch bulb and cell. Metals contain delocalised electrons which move freely between the metal ions. The electrons prevent the positive ions from repelling each other....
The potential difference (p.d) between two points is defined as the energy converted from electrical to other forms when one coulomb of positive charge passes between the two points.
The electromotive force is described as the energy converted from non- electrical forms to an electrical form, when one coulomb of positive charge passes through the cell. The e.m.f. of a supply is the work done in moving one coulomb of charge around a circuit....