Wales · WJECQ&A
ElectronicsQ&A by dot point
A short Q&A bank for every Wales Electronics syllabus dot point. Each question and answer is drawn directly from our worked dot-point page, so you can scan key concepts before opening the long-form answer.
Component 1: AC Circuits and Passive Filters
- AC signals and reactance: peak, peak-to-peak and RMS values, frequency and period, capacitive and inductive reactance, and the phase relationship between voltage and current.4Q&A pairs
- Passive filters: the RC low-pass and high-pass filter, the cut-off (break) frequency, the frequency response and the half-power point, gain in decibels, and the Bode plot.3Q&A pairs
Component 2: Audio and Power Systems
- Audio systems: the audio signal chain, the mixer based on a summing amplifier, tone control with filters, voltage and power amplification, gain in decibels, and driving a loudspeaker.2Q&A pairs
- Power supplies and mains: the transformer, rectification (half-wave and full-wave bridge), smoothing with a reservoir capacitor, voltage regulation, and electrical safety including fuses and earthing.2Q&A pairs
Component 1: Communications Systems
- Communication principles and modulation: the structure of a communication system, the need for a carrier, amplitude and frequency modulation, bandwidth, data rate, and noise and distortion.2Q&A pairs
- Wireless and optical transmission: radio-wave transmission and the aerial, attenuation and noise, optical-fibre transmission, total internal reflection, and multimode versus monomode fibre.2Q&A pairs
Core Concepts
- DC electrical circuits: charge, current, voltage and resistance, Ohm's law, series and parallel resistors, Kirchhoff's current and voltage laws, the potential divider, and power.4Q&A pairs
- Input and output sub-systems: sensors and input transducers (LDR, thermistor, switches) in potential dividers, and output transducers (LED, buzzer, relay, motor) with their driver and interfacing requirements.3Q&A pairs
- System synthesis: the systems approach, block diagrams, building a system from input, process and output sub-systems, and interfacing between blocks.3Q&A pairs
Component 1: Instrumentation and Timing Systems
- Instrumentation systems: sensors and transducers, the Wheatstone bridge, signal conditioning and amplification, calibration, and the use of the instrumentation amplifier.4Q&A pairs
- Timing circuits and oscillators: RC timing, the monostable and astable using the 555 timer or op-amp, the period and frequency equations, and the production of square waves and clock signals.2Q&A pairs
Component 1: Logic Systems
- Combinational logic design: deriving a circuit from a truth table or specification, sum-of-products form, simplification with Karnaugh maps, and building any function from NAND gates only.2Q&A pairs
- Logic gates and Boolean algebra: AND, OR, NOT, NAND, NOR, XOR and XNOR gates, truth tables, Boolean expressions, and the laws of Boolean algebra including De Morgan's theorems.9Q&A pairs
- Sequential logic and flip-flops: the difference between combinational and sequential logic, the SR latch, D-type and JK flip-flops, clocking, and using flip-flops to build counters and shift registers.2Q&A pairs
Component 2: Microcontroller Systems
- Microcontroller architecture and interfacing: the structure of a microcontroller (CPU, memory, ports), digital input and output ports, interfacing switches, sensors and output devices, and the on-chip ADC.2Q&A pairs
- Microcontroller programming: flowcharts, sequence, selection and iteration, input and output instructions, time delays, subroutines, and translating a system specification into a program.3Q&A pairs
Component 1: Operational Amplifiers
- Inverting and non-inverting amplifiers: negative feedback, the virtual earth, the closed-loop gain equations, and the voltage follower (buffer).4Q&A pairs
- Operational amplifier properties and the comparator: the ideal op-amp, open-loop gain, the comparator with and without hysteresis, and the Schmitt trigger.3Q&A pairs
- Summing, difference and instrumentation amplifiers: the summing (mixer) amplifier, the difference amplifier, and the instrumentation amplifier for small differential signals.3Q&A pairs
Component 1: Semiconductor Components
- 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.4Q&A pairs
- 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.3Q&A pairs
- 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.4Q&A pairs
Component 1: Signal Conversion
- Analogue-to-digital conversion: sampling, the sampling rate and the Nyquist criterion, quantisation, resolution and the number of bits, and quantisation error.3Q&A pairs
- Digital-to-analogue conversion: the summing-amplifier (weighted-resistor) DAC, the R-2R ladder DAC, the output equation, and reconstruction with a low-pass filter.3Q&A pairs