Basic Electronics Lecture Notes

Vocabulary flashcards summarizing key terms and definitions from the Basic Electronics lecture.

Electronics

Branch of physics that studies the emission, behavior, and effects of electrons and the devices that control them.

Basic Electronics

Study of electric circuits, components, and the flow of electricity through them.

Law of Conservation of Charge

Electric charge can neither be created nor destroyed—only transferred; total charge in a closed system is constant.

Electricity

Presence and flow of electric charges in the form of alternating current (AC) or direct current (DC).

Alternating Current (AC)

Current whose direction reverses periodically within a circuit.

Direct Current (DC)

Current that flows in one constant direction between power and ground.

Electric Current (I)

Rate of charge flow past a point in a circuit; measured in amperes (A).

Voltage (V)

Work done per unit charge to move a charge between two points; measured in volts.

Resistance (R)

Property of a conductor that limits current flow; measured in ohms (Ω).

Ohm's Law

Relationship V = I × R, stating that current through a conductor is directly proportional to the voltage across it.

Power (P)

Work done per unit time in an electrical circuit; P = I × V; measured in watts (W).

Circuit

Complete closed path that allows electric current to flow between power and ground.

Open Circuit

Broken path in which electric current cannot flow.

Series Circuit

Circuit configuration where components share the same current; total resistance is the sum of individual resistances.

Parallel Circuit

Circuit configuration where components share the same voltage; total current equals the sum of branch currents.

Resistor

Component that limits current flow; value indicated by colored bands; no polarity.

Potentiometer

Variable resistor whose value changes by turning a knob; no polarity.

Capacitor

Component that stores electric charge; capacitance C = q / V; may have polarity.

Equivalent Capacitance (Parallel)

For capacitors in parallel: C_eq = C₁ + C₂ + C₃ + …

Diode

Semiconductor that allows current in one direction only; forward drop ≈ 0.7 V; has polarity.

Light-Emitting Diode (LED)

Diode that emits light when forward-biased; typical forward voltage ≈ 2 V; has polarity.

Battery

Voltage source that supplies constant DC voltage with defined polarity.

Switch

Manually operated device that opens or closes an electrical connection.

Fuse

Protective device whose metal wire melts and opens the circuit when excessive current flows.

Circuit Breaker

Resettable device that mechanically interrupts a circuit under excessive current conditions.

Transistor (BJT)

Semiconductor device used for switching or amplification; available in NPN and PNP types.

Integrated Circuit (IC)

Miniaturized electronic circuit containing multiple components formed on a single chip.

Breadboard

Prototyping board with a grid of connected holes used to assemble temporary circuits without soldering.

Voltage Source

Device that provides a constant potential difference, thereby driving current in a circuit.

Electrical Safety Rule

If unsure of what to do, always ask questions before handling electrical equipment.

Current Safety Limit

Currents as low as 100 mA can be lethal; never short power terminals through your body.

Water Analogy

Compares voltage to pressure, current to flow rate, resistance to valve restriction, and power to useful output.