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Component 1: Semiconductor Components

3 dot points across 3 inquiry questions. Click any dot point for a focused answer with worked past exam questions where available.

How does a p-n junction work, and how do rectifier, Zener, light-emitting and photo diodes behave?

Diodes: n-type and p-type material, the p-n junction and depletion layer, forward and reverse bias, the diode I-V characteristic, and the rectifier, Zener, light-emitting and photodiode.
A focused answer to WJEC A-Level Electronics semiconductor diodes, covering n-type and p-type material, the p-n junction and depletion layer, forward and reverse bias, the diode I-V characteristic, and the behaviour and uses of rectifier, Zener, light-emitting and photodiodes.
12 min answer →

How does a single-transistor common-emitter amplifier work, and how is it biased to amplify a signal?

Transistors as amplifiers: the common-emitter voltage amplifier, biasing for a quiescent point, voltage gain, the role of the load and emitter resistors, and coupling capacitors.
A focused answer to WJEC A-Level Electronics transistor amplifiers, covering the common-emitter voltage amplifier, biasing to set the quiescent operating point, voltage gain from the collector and emitter resistors, coupling capacitors, and why the output is inverted.
12 min answer →

How do bipolar and MOSFET transistors act as electronic switches, and how do you design a switching stage?

Transistors as switches: the bipolar junction transistor and MOSFET, cut-off and saturation, the base (or gate) resistor, switching a load, and the Darlington pair.
A focused answer to WJEC A-Level Electronics transistor switching, covering the bipolar junction transistor and MOSFET as switches, cut-off and saturation, sizing the base or gate resistor, switching output loads, and the Darlington pair for high current gain.
12 min answer →