Specification points
WJEC A-level Electronics A490QS
174 points in 4 topics, with WJEC's codes and titles.
Grade boundaries·WJEC command words
Codes and titles are read by a script from WJEC's published specification and have not been checked by a person. What each point covers is in the specification itself: WJEC’s specification.
CC Core Concepts
- CC.1 System Synthesis
- CC.1(a) Inputs, processes, outputs and feedback
- CC.1(b) Sub-systems of complex systems
- CC.1(c) System diagrams
- CC.2 DC Electrical Circuits
- CC.2(a) Circuit symbols and circuit diagrams
- CC.2(b) Resistance and resistors in circuits
- CC.2(c) Resistors in series and parallel
- CC.2(d) Kirchhoff's laws and Thevenin's theorem
- CC.2(e) E24 resistor values
- CC.2(f) Capacitance
- CC.2(g) Capacitors in timing circuits; series and parallel
- CC.3 Input and Output Sub-systems
- CC.3(a) Sensors in voltage divider circuits
- CC.3(b) Characteristic curves of sensors
- CC.3(c) Voltage divider output voltages
- CC.3(d) Schmitt inverters for signal conditioning
- CC.3(e) Designing sensing circuits
- CC.3(f) Output devices in systems
- CC.4 Energy and Power
- CC.4(a) Power, energy and time
- CC.4(b) RMS voltage and current
- CC.4(c) Power relationships in AC and DC circuits
C1 Component 1: Principles of Electronics
- C1.1 Semiconductor Components
- C1.1(a) Conduction in n-type and p-type semiconductors
- C1.1(b) Conduction at a p-n junction
- C1.1(c) The photodiode
- C1.1(d) Properties of an n-channel enhancement MOSFET
- C1.1(e) LEDs, silicon diodes and zener diodes
- C1.1(f) LED series resistors and zener selection
- C1.1(g) MOSFETs and npn transistors in switching circuits
- C1.1(h) Transconductance of a MOSFET
- C1.1(i) MOSFET and transistor equations
- C1.2 Logic Systems
- C1.2(a) Logic gates, including XOR and XNOR
- C1.2(b) Truth tables for logic gates
- C1.2(c) Combining gates; NAND-gate simplification
- C1.2(d) Simplifying logic: Boolean algebra, Karnaugh maps, multiplexers
- C1.2(e) Designing logic gate circuits
- C1.2(f) De Morgan's theorem
- C1.2(g) Boolean identities
- C1.2(h) Applying Boolean identities
- C1.3 Operational Amplifiers
- C1.3(a) Ideal and typical op-amps
- C1.3(b) Op-amps with negative feedback; virtual earth
- C1.3(c) Op-amp comparators
- C1.3(d) Designing comparator switching circuits
- C1.3(e) Balanced bridge circuits
- C1.3(f) Voltage gain of an amplifier
- C1.3(g) Op-amp circuit configurations
- C1.3(h) Gain of inverting and non-inverting amplifiers
- C1.3(i) Comparator and voltage follower equations
- C1.3(j) Input impedance of op-amp circuits
- C1.3(k) Bandwidth of an amplifier
- C1.3(l) Designing single-stage amplifiers
- C1.3(m) Clipping and slew-rate distortion
- C1.3(n) MOSFET and transistor equations
- C1.4 Signal Conversion
- C1.4(a) Analogue and digital signal conversion
- C1.4(b) Summing amplifier as a DAC
- C1.4(c) Designing a DAC
- C1.4(d) Comparators as an ADC
- C1.4(e) Digitising audio signals
- C1.4(f) Flash converter ADCs
- C1.4(g) Resolution of a flash converter
- C1.4(h) Digital ramp and flash ADCs compared
- C1.5 AC Circuits and Passive Filters
- C1.5(a) V-t, I-t and P-t graphs for resistive loads
- C1.5(b) RMS and peak values
- C1.5(c) Reactance and impedance
- C1.5(d) Passive RC filter responses
- C1.5(e) Designing passive filters
- C1.5(f) MOSFET and transistor equations
- C1.6 Communications Systems
- C1.6(a) Communication as information transfer
- C1.6(b) Structure of a communication system
- C1.6(c) Bandwidth, data rate and information capacity
- C1.6(d) Frequency and time division multiplexing
- C1.6(e) Filters in communication systems
- C1.6(f) The decibel scale
- C1.6(g) Differentiate between noise and distortion
- C1.6(h) Total gain in a communication system
- C1.6(i) Signal-to-noise ratio
- C1.6(j) Signal attenuation
- C1.7 Wireless Transmission
- C1.7(a) Regions of the radio spectrum
- C1.7(b) Amplitude and frequency modulation
- C1.7(c) AM and FM waveforms
- C1.8 Instrumentation Systems
- C1.8(a) Op-amp difference amplifiers
- C1.8(b) Instrumentation amplifiers
- C1.8(c) Bridge circuits with thermistors and strain gauges
- C1.8(d) Slotted and encoded discs
- C1.8(e) Gray coding and binary coding
- C1.8(f) Processing slotted and encoded disc outputs
C2 Component 2: Application of Electronics
- C2.1 Timing Circuits
- C2.1(a) RC time constant
- C2.1(b) Exponential charging and discharging
- C2.1(c) MOSFET and transistor equations
- C2.1(d) Finding T, R and C from graphs
- C2.1(e) RC debouncing of switches
- C2.1(f) Properties of monostable circuits
- C2.1(g) Monostable time-delay circuits
- C2.1(h) Astable circuits as pulse generators
- C2.1(i) Designing astable circuits
- C2.1(j) 555 timer monostable and astable circuits
- C2.2 Sequential Logic Systems
- C2.2(a) SR latch from NAND gates
- C2.2(b) Propagation delays in sequential systems
- C2.2(c) Timing diagrams for sequential logic
- C2.2(d) D-type flip-flops: inputs, outputs and uses
- C2.2(e) Sequencing with a 4-bit counter and combinational logic
- C2.2(f) Two-digit decimal counting systems
- C2.2(g) Binary, decimal, hexadecimal and BCD conversions
- C2.2(h) Sequence generators from D-type flip-flops
- C2.3 Microcontrollers
- C2.3(a) Flowchart programs for microcontrollers
- C2.3(b) Structure of a PIC microcontroller
- C2.3(c) Interrupts
- C2.3(d) Applications of PIC microcontrollers
- C2.3(e) Programming PIC microcontrollers in assembler
- C2.4 Digital Communications
- C2.4(a) Schmitt trigger signal regeneration
- C2.4(b) Pulse modulation techniques
- C2.4(c) Pulse code modulation systems
- C2.4(d) Sampling frequency and Nyquist theorem
- C2.4(e) Time division multiplexing in PCM links
- C2.4(f) Channel limits in PCM links
- C2.5 Optical Communication
- C2.5(a) Transmission in optical fibres
- C2.5(b) Losses in optical fibre communication
- C2.5(c) Converting between electrical and optical signals
- C2.5(d) LED and laser sources in optical transmitters
- C2.6 Mains Power Supply Systems
- C2.6(a) Half-wave and full-wave rectification
- C2.6(b) Capacitors and loads in simple power supplies
- C2.6(c) Ripple voltage equation
- C2.6(d) Zener-regulated power supplies
- C2.6(e) Load and line regulation
- C2.6(f) Designing a voltage regulator
- C2.6(g) Regulator gain equation
- C2.7 High Power Switching Systems
- C2.7(a) Thyristors and triacs for switching loads
- C2.7(b) Thyristor characteristics and conduction
- C2.7(c) DC thyristor switching and capacitor commutation
- C2.7(d) AC phase control with triac and diac
- C2.7(e) Phase control equation
- C2.8 Audio Systems
- C2.8(a) Structure of a simple audio system
- C2.8(b) Multi-stage voltage preamplifiers
- C2.8(c) Summing amplifier mixer circuits
- C2.8(d) First-order active tone filters
- C2.8(e) Maximum power transfer theorem
- C2.8(f) Emitter and source follower power amplifiers
- C2.8(g) Push-pull power amplifiers
- C2.8(h) Waveforms of filters and power amplifiers
- C2.8(i) Crossover distortion and negative feedback
C3 Component 3: Extended system design and realisation tasks
- C3(a) Analysing a problem to develop solutions
- C3(b) Developing a design specification
- C3(c) Proposing an electronic system of sub-systems
- C3(d) Predicting how electronic systems behave
- C3(e) Designing, building, modelling and modifying an electronic system
- C3(f) Planning tests and choosing techniques and instruments
- C3(g) Evaluating practical risks
- C3(h) Carrying out tests accurately and safely
- C3(i) Making and recording measurements on circuits
- C3(j) Reporting results using scientific conventions
- C3(k) Evaluating the system against the design specification
- C3(l) Suggesting improvements after evaluation
- C3(m) Designing and programming a microcontroller system in assembly language