Basic Electrical Theory and Circuits Quiz

Study Notes

Direct Current (DC) flows in one direction.
Alternating Current (AC) reverses direction periodically.
Voltage is the electrical pressure that drives current.
Current is the flow of electrons.
Resistance opposes the flow of current.
Ohm's Law: Voltage = Current x Resistance (V = IR).
Power (Watts) = Voltage x Current (P = VI).
Series circuits: Components are connected end-to-end. Current is the same through all components, voltage is divided.
Parallel circuits: Components are connected across each other. Voltage is the same across all components, current divides.

Series Circuits:
Components connected linearly.
Current is the same throughout the circuit.
Total resistance is the sum of individual resistances.
Voltage drop across each component is proportional to its resistance.
Parallel Circuits:
Components connected across each other.
Voltage is the same across all components.
Total conductance (reciprocal of resistance) is the sum of individual conductances.
Current divides among branches, inversely proportional to their resistances.

AC circuits involve sinusoidal voltage and current.
Frequency is the number of cycles per second (Hz).
Impedance is the opposition to AC current flow, encompassing resistance, inductance, and capacitance.
Inductance opposes changes in current flow.
Capacitance stores energy in an electric field.
Resonance occurs when the inductive reactance and capacitive reactance cancel each other out often in AC circuits, resulting in a low impedance, therefore high current.

Always follow safety procedures, especially when working with electricity.
Use appropriate personal protective equipment (PPE).
Grounding is crucial for safety, preventing accidental shocks.
Never work on live wires unless necessary and authorized.
Disconnect power before working on any electrical system.
Be aware of potential hazards like frayed wires, exposed connections, and overloaded circuits.

Power gates regulate the flow of electricity to equipment.
They often contain circuit breakers, fuses, and other protective devices.
Control systems automate operations through sensors, relays, and other electronic components.
PLC (Programmable Logic Controllers) are used for complex automation tasks.
SCADA (Supervisory Control and Data Acquisition) systems monitor and control large-scale systems.
Safety interlocks ensures equipment is not operated in unsafe conditions.
Gate actuators are often electrically controlled and provide precise movements for gates

Common electrical problems include tripped circuit breakers, flickering lights, and malfunctioning appliances.
Identifying the cause of a problem involves systematically checking components and connections.
Accurate voltage, current and resistance measurements are essential tools in troubleshooting.