Electric voltage (U)
Potential difference between two points. Unit: Volt (V). UAB = VA − VB.
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Lesson overview
This lesson brings together the PDF, study notes and chapter flow so you can revise The Transistor without losing the thread.
Electric voltage (U)
Potential difference between two points. Unit: Volt (V). UAB = VA − VB.
Current intensity (I)
I = Q / t. Charge passing per unit time. Unit: Ampere (A).
Ohm's law
U = R·I for an ohmic conductor. R in Ohm (Ω).
Resistors in series
Req = R₁ + R₂ + … The same current flows through all resistors.
Resistors in parallel
1/Req = 1/R₁ + 1/R₂ + … Same voltage across all resistors.
Kirchhoff's laws
Node law: ΣI in = ΣI out. Mesh law: ΣU = 0 around a loop.
Electric power (P)
P = U·I = R·I² = U²/R. Unit: Watt (W).
Simulation 1 - General Electricity
Computer modeling.
Simulation 2 - General Electricity
Computer modeling.
Simulation 3 - General Electricity
Computer modeling.
Simulation 4 - General Electricity
Computer modeling.
Simulation 5 - General Electricity
Computer modeling.
Scientific method
Read data, identify the system, choose the model, write relations with SI units, then check the order of magnitude.
Exam focus
Precise definitions, labelled diagrams, unit conversions, document analysis, and justified numerical results.
Core quantities
Voltage U in volts, current I in amperes, resistance R in ohms, power P in watts.