google_ad_client = "ca-pub-4024712781135542"; EMF vs potential difference. On a voltage-time graph, this would appear as a curve alternating between positive and negative voltages. , eV When resistance is increased in a circuit, for example by adding more electrical components, the current decreases as a result. Read the Electronics Weekly @ 60 supplement . Electrical current transfers energy around circuits. Since I havent heard of the term GCSE before, Ill assume that it isnt part of the culture here in the USA? google_ad_slot = "0360786191"; Potential Difference formula:** V = I x R** The potential difference (which is the same as voltage) is equal to the amount of current multiplied by the resistance. In a series circuit, the total resistance across all of the components (the 'net resistance') increases as more components are added. EMF seems like it relates to the era where all of electrical design was focused on electromagnetics motors, generators, transformers.