Introduction to Electricity Electricity is the flow of electric charges, typically electrons, through a conductor. This topic covers the fundamental concepts an...
Electricity is the flow of electric charges, typically electrons, through a conductor. This topic covers the fundamental concepts and principles governing electric circuits and electromagnetic effects.
Electric charge is a fundamental property of matter, with protons carrying a positive charge and electrons carrying a negative charge. Current is the rate of flow of electric charges through a conductor, measured in amperes (A).
Potential difference, or voltage (V), is the driving force that causes charges to flow in a circuit. It is measured in volts (V) and represents the potential energy difference between two points in an electric field.
Resistance (R) is a measure of the opposition to the flow of electric current in a circuit, measured in ohms (Ω). Ohm's Law states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) across it and inversely proportional to its resistance (R), expressed as:
V = IR
An electric circuit is a closed path through which electric charges can flow. This topic covers the analysis of series and parallel circuits, examining how current, potential difference, and total resistance behave in each configuration.
Problem: In a series circuit with three resistors of 10 Ω, 20 Ω, and 30 Ω, and a supply voltage of 12 V, find the total resistance, current, and potential difference across each resistor.
Solution:
Electrical power (P) is the rate at which energy is transferred or dissipated in an electric circuit, calculated as P = IV or P = I²R. Electrical energy (E) is the amount of energy transferred or dissipated over time, calculated as E = Pt or E = QV.
This topic covers the principles of domestic electricity, including the National Grid, fuses, and earth wires for safety. It also explores the concepts of static electricity, electric fields, and electrostatic forces.