1. Electrical Fundamentals

1.1 Basic Electrical Quantities

1.1.1 Voltage, Current, and Resistance:
Voltage is the potential difference between two points in an electric field, measured in volts (V). Current is the flow of electric charge through a conductor, measured in amperes (A). Resistance is the opposition to the flow of current, measured in ohms (Ω). Ohm’s Law relates these quantities with the formula V = IR.

1.1.2 Power and Energy:
Power is the rate at which electrical energy is transferred by a circuit and is measured in watts (W). It is calculated using the formulas P = VI or P = I²R. Energy consumption, often billed in kilowatt-hours (kWh), is the total power used over time and is crucial for managing electricity usage in homes and industries.

1.2 Circuit Elements and Tools

1.2.1 Passive Components:
Resistors limit current, capacitors store and release energy, and inductors resist changes in current. These components are essential in shaping the behavior of electrical circuits. They are used in filtering, timing, and energy storage applications. Color codes on resistors indicate their resistance value.

1.2.2 Electrical Tools and Safety:
Common tools include pliers, wire strippers, multimeters, and screwdrivers. Safety gear such as gloves, safety boots, and insulated tools protect against electric shocks and injuries. Safe working practices include verifying circuits are de-energized and using lock-out/tag-out procedures.