Electric

Study Notes

An electric circuit is a closed path along which an electric current flows.
A circuit must contain a source of electrical energy (e.g., battery, generator) to provide the driving force.
Components like resistors, capacitors, inductors, and diodes are connected to control the flow of current.
Closed-loop path: The circuit must form a complete loop for current to flow continuously.
Electrical current is the flow of electric charge (electrons) through a conductor.
Voltage is the electrical potential difference between two points in a circuit. It pushes the current.
Resistance is the opposition to the flow of current in a circuit. Measured in ohms (Ω).

Series Circuit: Components are connected end-to-end in a single path.
- Total resistance: The sum of individual resistances.
- Current: The same current flows through all components.
- Voltage: Voltage divides across each component proportionally to its resistance.
Parallel Circuit: Components are connected across two common points.
- Total resistance: Less than the smallest individual resistance.
- Current: Current divides among branches, with the total current being the sum of the currents in each branch.
- Voltage: The voltage across each component is the same.

Ohm's law relates voltage, current, and resistance in a simple circuit.
V = I × R, where:
- V = voltage (volts)
- I = current (amperes)
- R = resistance (ohms)

Kirchhoff's current law (KCL): The total current entering a junction is equal to the total current leaving it.
Kirchhoff's voltage law (KVL): The algebraic sum of the voltages around any closed loop in a circuit is zero.

Power is the rate at which energy is dissipated in a circuit.
P = I × V, where:
- P = power (watts)
- I = current (amperes)
- V = voltage (volts)

Loop analysis: Using Kirchhoff's voltage law to solve for the currents flowing in each branch of the circuit.
Node analysis: Using Kirchhoff's current law to solve for the voltages at various points in the circuit.

Resistor: A component that opposes the flow of current.
Capacitor: A component that stores electrical energy in an electric field.
Inductor: A component that stores energy in a magnetic field.
Switch: A component that opens or closes a circuit to control the flow of current.
Source: Provides electrical energy (e.g., battery, generator, transformer).
Diode: Component that allows current to flow in one direction only.

AC circuits involve alternating current (current that changes direction periodically).
AC sources use sinusoidal waveforms to generate current.
Key concepts in AC circuits are frequency, impedance, reactance (capacitive and inductive).
AC circuit analysis differs from DC, needing concepts like phase, complex numbers, and impedance diagrams.

Electrical circuits require proper safety measures to prevent electric shock and fire hazards.
Isolation, grounding, circuit breakers, and fuses are critical for safety.