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Pop Quiz Due to the Earth’s core, the Earth acts like a giant _________. True or False Mono poles (only one pole) exists. True or False If the domains are aligned, the object is magnetic. How do opposite magnetic poles and like magnetic poles act or behave?
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Pop Quiz • Due to the Earth’s core, the Earth acts like a giant _________. • True or False Mono poles (only one pole) exists. • True or False If the domains are aligned, the object is magnetic. • How do opposite magnetic poles and like magnetic poles act or behave? • True or False If you suspend a magnet in the air, the north end of the magnet will point to the south magnetic pole.
Magnets!!!!!! I) What is a magnet? – a body that repels or attracts iron and certain other materials toward it and produces a magnetic field outside of itself.
A) All magnets have 2 poles. North and South B) One pole will always point to the North if rotating freely. It is called the north geographic pole (or the South magnetic pole). C) Magnetism (magnetic force) – the power of the magnet (strength of the force) D) Magnetism is greatest at the poles of the magnet
E) Law for magnetic poles: Opposite poles attract each other. Like poles repel each other F) Magnetic poles always appear in pairs. Mono poles do not exist!!! (Mono pole is just 1 pole) G) Magnetic field – area around magnet in which magnetic forces are present
II) What makes materials magnetic? A. Domains – regions of atoms grouped together (like tiny magnets) If the domains are aligned the object is magnetic If the domains are arranged randomly the object isn’t magnetic.
III. Types of Magnets • Ferromagnets – magnets with strong magnetic properties (iron, nickel, cobalt) • Temporary Magnets – magnets that are easily magnetized and also lose their magnetization easily (soft iron) • Permanent magnets – magnets that are difficult to magnetize and keep their magnetic properties better (alnico) – an alloy of aluminum, nickel and cobalt • Electromagnet – talk about later
IV. Due to the Earth’s core, the Earth acts like a giant magnet. As the earth rotates, the outer core’s liquid flows & causes electric charges to move, creating a magnetic field.
A) An aurora is a curtain of light caused by the Earth’s magnetic field. Aurora Borealis or The Northern Lights It’s when the sun’s charged particles (radiation) interact with oxygen and nitrogen atoms in our atmosphere to emit light of different colors.
Electricity and Magnetism Can a magnetic field be created from an electric field??? YES! A. An Electromagnet is a current-carrying wire wrapped around an iron core. 1. The magnetic field of an electromagnet is turned on and off when the electric current is turned on or off. 2. Current-carrying wires produce a magnetic field and can attract or repel each other as if they were two magnets!!
3. An example of this is an electric motor. a. An electric motor converts electrical energy (from chemical energy) into kinetic energy and runs by using the magnetic field formed by a current-carrying wire formed into a loop. 4. Hans Christian Oersted discovered that a wire carrying an electric current produces a magnetic field.
A doorbell A standard bell ringer design works just like a buzzer except the contact arm is attached to a long clapper that hits a metal bell.
Electricity from magnetism Can electric current be produced from a magnetic field?? YES!...but the magnetic field must be a changing magnetic field!!! What is it called??? ELECTROMAGNETIC INDUCTION
Electromagnetic Induction- the process by which an electric current is produced by a changing magnetic field 1. Michael Faraday discovered electromagnetic induction Examples of electromagnetic induction include: 1. Generators – convert kinetic into electrical energy
2. Transformers – increase and decrease the voltage of an alternating current (AC) using electromagnetic induction There are two types of transformers: a. step-up transformer-increases voltage b. step-down transformer-decreases voltage
Electric Circuits Questions • How many different circuits do you see in the household circuits diagram? • Are household circuits series circuits or parallel circuits? • Explain what would happen if the circuits were the other kind. • If the refrigerator in the diagram blew a fuse, what other appliance(s) would be affected? • If the coffee maker blew a fuse, what other appliances) would be affected? • What other appliances would be affected if the living room fan blew a fuse?
A typical small substation The transmission lines entering the substation and passing through the switch tower The switch tower and the main transformer