The current (I) through a component depends on both the resistance (R) of the component and the potential difference (V) across the component. The greater the resistance of the component the smaller the current for a given potential difference (pd) across the component. • Questions will be set using the term potential difference. Students will gain credit for the correct use of either potential difference or voltage. • Current, potential difference or resistance can be calculated using the equation: potential difference = current × resistance, V = I R (potential difference, V, in volts, V; current, I, in amperes, A (amp is acceptable for ampere); resistance, R, in ohms, Ω) • Students should be able to recall and apply this equation.