A2 Unit 19 Capacitance

Sperm Transport and Capacitation

Capacitors

Electrostatics: Charge, Fields, Gauss's Law, and Capacitance

: Systems Engineering – Unit 3 Revision Study Guide Electrical & Energy Systems 1. The Engineering Process & Systems Thinking 1.1 The Engineering Process Stages You must know the sequence and purpose of each stage: 1. Investigate & design 2. Plan 3. Produce a solution 4. Test and diagnose 5. Evaluate and report 6. Modify and improve Once a system is built, the next stage is always “Test and diagnose”. 1.2 IPO Diagrams (Input–Process–Output) Used to analyse and explain systems. Example: Home Security Alarm • Inputs: Motion sensors, door switches, keypad input • Process: Microcontroller compares input to programmed logic • Outputs: Alarm siren, alert light, SMS notification Be ready to label inputs, processes, and outputs clearly. 2. Energy Sources & Sustainability 2.1 Renewable vs Non-Renewable • Renewable: Solar, wind, hydro, tidal, biomass, geothermal • Non-renewable: Coal, oil, gas, nuclear (alternative but not renewable) Geothermal energy comes from heated groundwater. 2.2 Advantages & Disadvantages (Exam Favourite) Wind Power – Advantages • Renewable • Zero greenhouse emissions during operation • Low operating cost • Scalable • Reduces fossil fuel dependence Coal Power – Disadvantages • High CO₂ emissions • Non-renewable • Air pollution • Thermal inefficiency • Environmental damage You will be asked to: • Compare energy sources • Justify one over another • Give an opinion with reasoning 3. Energy Transformations Know energy chains in order: Examples • Wind turbine: Kinetic → Mechanical → Electrical • Hydro power: Potential → Kinetic → Mechanical → Electrical • Solar PV: Radiant → Electrical 4. Efficiency Calculations HIGH PRIORITY 4.1 Formula Efficiency= Useful output energy Total input energy × 100% 4.2 Combined Efficiency Multiply efficiencies as decimals: Example: • Solar panel: 40% → 0.40 • Battery: 80% → 0.80 0.40 × 0.80 = 0.32 = 32% Combined efficiency = 32% 5. Electrical Fundamentals 5.1 Current Types • AC (Alternating Current): Household power, wind turbines • DC (Direct Current): Batteries, solar panels 5.2 Frequency & Period 1 𝑓 = 𝑇 • Australia mains electricity = 50 Hz • Direction changes 50 times per second Example: • Period = 0.005 s 𝑓 = 1 ÷ 0.005 = 200 Hz 6. Power, Work & Energy Calculations 6.1 Power 𝑊 𝑃 = or𝑃 = 𝑉 × 𝐼 𝑡 Example: • 1,000,000 J in 50 s 𝑃 = 1,000,000 ÷ 50 = 20,000 W 6.2 Work 𝑊 = 𝐹 × 𝑑 Example: • 2000 N × 10 m = 20,000 J 7. Batteries & Electrical Storage 7.1 Series vs Parallel • Series: Voltage adds • Parallel: Capacity (Ah) adds Example: • 4 × 12 V batteries in series = 48 V 7.2 Battery Runtime Total energy Time (h)= Power of load 8. Circuit Theory 8.1 Ohm’s Law 𝑉 = 𝐼 × 𝑅 8.2 Resistance • Series: 𝑅𝑇 = 𝑅1 + 𝑅2 + 𝑅3 • Parallel: 1 1 1 = + 𝑅𝑇 𝑅1 𝑅2 8.3 Capacitors • Series: inverse rule • Parallel: add values directly 9. Electrical Components & Symbols You must identify: • Resistor • Variable resistor (potentiometer) • Capacitor • Cell / Battery • LDR (light-dependent resistor) • LED • Diode • Thermistor • Switch types: SPST, SPDT, DPDT LED does not detect light LDR, phototransistor do 10. Transformers Formula 𝑉 𝑠 𝑁 𝑠 = 𝑉 𝑝 𝑁 𝑝 Example: • 40 primary, 800 secondary • Input = 240 V 𝑉 𝑠 = 240 × (800 ÷ 40) = 4800𝑉 Used to step up voltage → reduce current → reduce power loss 11. Power Transmission Why Voltage Is Stepped-Up • Reduces current • Minimises power loss as heat • Improves efficiency • Allows thinner cables • Enables long-distance transmission 12. Power Electronics Rectifier • Converts AC to DC H-Bridge + PWM • Technique: Pulse Width Modulation (PWM) • Purpose: Convert DC into simulated AC & control motor speed 13. Semiconductors • Doping: Adding impurities to silicon • Creates diodes and transistors • Enables controlled current flow 14. Safety & Standards Before using 230 V power tools: Must have a current electrical safety tag 15

AC/DC Theory Chapter 18 Inductive Resistive Capacitive Circuits

Capacitance and Dielectrics

INEL 15140 Capacitance

30060 Capacitor Start Ac Motors

30070 Permanent Capacirot and Two Capacitor Motors

Inductance and Capacitance

Inductance and Capacitance

Capactiors and Inductors

Introduction to Capacitors and Inductors

Capacitance and Dielectrics

Electrostatics: Charge, Fields, Gauss's Law, and Capacitance

Capacitance, Current & Resistance

Capacitance

Electrostatics and Capacitance

Capacitors and Dielectrics (from lecture 15)