Electromagnetism
Understanding electricity, magnetism, and electromagnetic waves
Subcategories
Electric Current & Circuits
Understanding electric current, resistance, and how circuits work
Electromagnetic Waves
Understanding electromagnetic radiation, the spectrum, and wave applications
Electrostatics
Understanding static electricity, electric fields, and electric potential
Magnetism
Understanding magnetic fields, magnetic forces, and electromagnetic induction
Topics
How do batteries work?
Batteries work by converting chemical energy into electrical energy through chemical reactions. They contain two electrodes (anode and cathode) separated by an electrolyte, with chemical reactions creating voltage that drives current through circuits.
Read more →How do circuits work?
Circuits work by providing a complete path for electric current to flow from a voltage source through components and back. Current flows when the circuit is closed, powering devices and allowing electricity to do work.
Read more →What is electric current?
Electric current is the flow of electric charge, typically electrons moving through a conductor. It's measured in amperes (amps) and represents the rate at which charge flows through a circuit.
Read more →What is Ohm's law?
Ohm's law states that voltage equals current times resistance (V = I × R). It describes the relationship between voltage, current, and resistance in electrical circuits, showing how these quantities relate.
Read more →What is resistance?
Resistance is a material's opposition to electric current flow. It's measured in ohms and determines how much current flows for a given voltage. Higher resistance means less current flows.
Read more →How does radio work?
Radio works by transmitting information on electromagnetic radio waves. A transmitter converts sound or data into radio waves that travel through space, and a receiver picks up these waves and converts them back into sound or data.
Read more →How does WiFi work?
WiFi works by transmitting data using radio waves in the microwave frequency range (2.4 GHz and 5 GHz). A router converts digital data into radio signals that devices receive and convert back to data, enabling wireless internet access.
Read more →What are electromagnetic waves?
Electromagnetic waves are oscillating electric and magnetic fields that travel through space, transferring energy without requiring a medium. They include radio waves, microwaves, light, X-rays, and gamma rays, all traveling at the speed of light.
Read more →What is light?
Light is electromagnetic radiation that our eyes can detect, with wavelengths between about 400-700 nanometers. It behaves as both a wave and a particle (photon), traveling at the speed of light and carrying energy.
Read more →What is the electromagnetic spectrum?
The electromagnetic spectrum is the full range of all possible frequencies of electromagnetic radiation, from low-frequency radio waves to high-frequency gamma rays. It includes radio, microwave, infrared, visible light, ultraviolet, X-ray, and gamma ray regions.
Read more →What is an electric field?
An electric field is a region around an electric charge where electric forces act on other charges. It represents the force per unit charge and describes how charges influence each other through space, even without direct contact.
Read more →What is electricity?
Electricity is the flow of electric charge, typically electrons moving through a conductor. It involves electric current (flowing charge), voltage (electrical pressure), and can power devices and create magnetic fields.
Read more →What is static electricity?
Static electricity is the buildup of electric charge on an object's surface. It occurs when electrons transfer between objects through contact or friction, creating an imbalance of charge that can cause sparks or attraction.
Read more →What is voltage?
Voltage is the electrical potential difference between two points, representing the 'pressure' that drives electric current. It's measured in volts and determines how strongly charge is pushed through a circuit.
Read more →Why do we get electric shocks?
We get electric shocks when electric charge suddenly flows through our body. This can happen from static electricity (charge buildup discharging) or from contact with live electrical circuits, causing a painful sensation.
Read more →How do magnets work?
Magnets work through magnetic fields created by aligned magnetic domains in materials. Permanent magnets have domains aligned by their atomic structure, while electromagnets create fields through electric current flowing through coils.
Read more →How does a compass work?
A compass works because its magnetic needle aligns with Earth's magnetic field. The needle is a small magnet that points toward magnetic north, allowing navigation by showing direction relative to Earth's magnetic poles.
Read more →What is a magnetic field?
A magnetic field is a region around a magnet or moving electric charge where magnetic forces act on other magnets or moving charges. It's invisible but can be detected by its effects on magnetic materials and compasses.
Read more →What is electromagnetic induction?
Electromagnetic induction is the process of generating electric current by changing magnetic fields. When a magnetic field changes near a conductor, it creates an electric field that drives current, as described by Faraday's law.
Read more →Why do magnets attract metal?
Magnets attract certain metals (like iron, nickel, and cobalt) because these ferromagnetic materials have unpaired electrons that align with the magnet's magnetic field, creating attraction through magnetic forces.
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