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1. Description Participants must answer questions and perform tasks about electricity and magnetism. This means the event includes: Conceptual questions Mathematical calculations Circuit analysis Hands-on lab tasks Team size: Up to 2 people Time: About 50 minutes Calculator: Class III (advanced scientific calculator allowed) 2. Event Parameters (What You Can Bring) a. Notes and Resources You can bring unlimited notes. Allowed formats: Binders Notebooks Printed sheets Laminated pages Tabs and labels Unlike many events, there is no limit on notes. b. Writing utensils and calculators Each team can bring: Pens/pencils
Two Class III calculators c. Equipment for hands-on tasks Event supervisors provide: wires resistors power supplies measurement tools You don’t need to bring these. d. Multimeter You may bring your own multimeter. A multimeter measures: voltage current resistance
3. The Competition The event has two parts : Written test Hands-on tasks PART I – Written Test Topics The written exam tests knowledge of electricity and magnetism. Answers must use: metric units
lightning Hazards: sparks electronic damage fires near flammable materials Capacitance A capacitor stores electrical energy. Capacitance: C=QVC=VQ Where: C = capacitance Q = charge V = voltage Unit: farad (F) ii. Direct Current (DC) DC current flows in one direction. Examples: batteries solar cells DC is used in: electronics computers phones Hazards: electrical burns
shocks iii. Alternating Current (AC) AC current reverses direction periodically. Example: household electricity. In the US: Frequency = 60 Hz AC powers: appliances lights motors Hazards: electric shock electrocution iv. Electrical Quantities and Units Key electrical quantities: Quantity Symb ol Unit Current I ampere (A) Voltage V volt (V) Resistanc e R ohm (Ω) Power P watt (W) Energy E joule (J)
Electromagnets Electric current through a wire coil creates a magnetic field. Example: coil around iron nail. Transformers Transformers change voltage in AC circuits. Two coils: primary coil secondary coil Used in power transmission. Motors and Generators Electric motor: electric energy → mechanical motion Electric generator: mechanical motion → electricity Both use magnetic fields. Right-Hand Rule Used to determine magnetic field direction. Thumb → current direction Fingers → magnetic field direction vi. Electrical Control Devices These control or protect circuits. Examples: Switch Opens or closes a circuit.
Relay Electromagnetic switch. Fuse Thin wire that melts when current too high. Prevents fire. Circuit Breaker Automatically shuts off power if current too high. Used in homes. Ground Fault Circuit Interrupter (GFCI) Protects against electric shock. Used in bathrooms and kitchens. vii. Circuit Calculations You must analyze circuits. Two types: Series Circuit Components in one path. Properties: same current everywhere resistances add Rtotal=R1+R2+R3Rtotal=R1+R2+R Parallel Circuit
x. Advanced Topics (States/Nationals) These appear only at higher competitions. LED (Light Emitting Diode) A semiconductor that emits light when current flows. Uses a PN junction. PN Junctions Boundary between p-type and n-type semiconductors. Examples: diodes transistors Transistors Types: PNP NPN Used for: amplification switching Operational Amplifiers (Op-Amps) Electronic circuits that amplify voltage signals. Used in: audio systems sensors signal processing
Topics NOT Included You do NOT need to study : advanced semiconductor physics AC circuit theory frequency analysis inductance calculus-based electrical analysis oscilloscopes 3-phase power PART II – Hands-On Tasks You must perform practical electrical tasks.
1. Identify a Mystery Resistor Using only voltage measurements: Use Ohm’s Law to calculate resistance. 2. Calculate Power Measure voltage and current. Use: P=IVP=IV 3. LED Circuit You may be given: wires resistors batteries
