Electricity & Circuits
10 concepts in Physics
Electricity and circuits explore how electric charge flows through conductors and how we harness that flow to power everything from light bulbs to computers. Students learn the foundational quantities — charge, current, voltage, and resistance — and discover how they relate through Ohm's law. They study series and parallel circuits, learning to predict how adding components changes the behavior of the whole system. Circuit diagrams provide a universal language for representing electrical systems. Electrical power and energy calculations connect circuit theory to real-world concerns like household electricity bills and device ratings. Understanding circuits is essential for physics, engineering, and everyday technological literacy, and it provides the conceptual bridge to more advanced topics in electromagnetism and electronics.
Suggested learning path: Start with electric charge and current as the flow of charge, then study voltage and resistance, apply Ohm's law, and build understanding of series and parallel circuits before exploring electrical power.
Electric Charge
A fundamental property of matter that causes it to experience a force in an electromagnetic field. Measured in coulombs (C).
Electric Current
The rate of flow of electric charge through a conductor. Measured in amperes (A).
Voltage
The difference in electric potential energy per unit charge between two points. Measured in volts (V).
Resistance
A measure of how much a material opposes the flow of electric current. Measured in ohms (\(\Omega\)).
Ohm's Law
The relationship stating that voltage across a conductor equals the current through it multiplied by its resistance.
Circuit
A closed loop of conducting material through which electric current can flow, typically including a power source and one or more components.
Series Circuit
A circuit in which components are connected end-to-end, so the same current flows through each one.
Parallel Circuit
A circuit in which components are connected across the same two points, so each has the same voltage across it.
Circuit Diagram
A simplified drawing of an electrical circuit using standardized symbols for components like batteries, resistors, switches, and bulbs.
Electrical Power
The rate at which electrical energy is converted to other forms of energy (heat, light, motion). Measured in watts (W).