WJEC A Level Electronics ET1 — Unit Papers & Mark Schemes

ET1 rewards students who can combine calculation with explanation. When solving resistive circuit problems, draw a clear circuit diagram, identify series and parallel sections, and show each step of your calculation. Always state units and check your answer is physically reasonable — a potential divider output higher than the supply voltage signals an error. Digital logic questions in ET1 test the ability to derive logic expressions from truth tables and simplify them using Boolean algebra or Karnaugh maps. Practise both techniques until you can apply them without hesitation. When drawing Karnaugh maps, pay attention to the Gray code ordering of variables and loop groups of 1, 2, 4, or 8 cells. Transistor-as-switch questions test whether you understand the conditions for saturation and cut-off. Know the minimum base current required to saturate a transistor for a given collector current and load resistance, and be able to calculate the base resistor value needed to ensure reliable switching.