Electromagnetism and magnetic domains

• Magnetic domains: a group of atoms or molecules that are aligned, the materials that made up of these atoms have strong magnetic properties.
• Magnets always have two poles, the south and north poles
• Magnets can be destroyed by heating or constant hitting
• Heat makes the molecules in the magnetic domains vibrate and break out from their ordered patterns resulting in rearrangement of magnetic domains
• Law of poles: Like magnetic poles repel, and unlike magnetic pole attract.
• Electromagnetism: physical interaction of electric charge, magnetic moments, and electromagnetic fields1
• An electromagnetic field can be static, slowly changing, or form waves
• Electromagnetic waves are generally known as light an obey laws of optics
• A changing magnetic field creates an electric field and a changing electric field creates magnetic field
• Magnetic Induction: or electromagnetic induction refers to the production of voltage across an electrical conductor placed inside a varying magnetic field.
• Electromagnetic induction: creation of electromotive force in electric conductor and creation of current moving through a static magnetic field
• Magnetic Induction was given name by Faraday. Is the act of becoming magnetized which certain substances perform when they are placed in a magnetic field
• Magnetic field: region where a magnet or conductor convey electric current
• Several ways of changing the magnetic field in a circuit to induced EMF has 3
• 1. continuous movement of magnet into the coil of wire
• 2. changing the orientation of the coil of wire with respect to the magnetic field
• 3. applying a changing electric current in the circuit
• a quantitative relationship expressing that a changing magnetic field induces a voltage in a circuit, developed based on experimental observations in 1831 by Michael Faraday.
• Faraday's law of magnetic inuduction:
• Lenz Law: the current induced to a circuit is due to a change in magnetic field directed to opposed the motion
• Lenz Law hand rule: thumb points the direction of current and fingers point the direction of magnetic field
• Lenz’s Law and Faraday’s Law: both govern how magnetic fields are generated by conductors carrying AC and DC currents
• Lenz's law states the direction of an induced current, and faraday's law relates the magnitude of the induced back EMF