Science Notes: Stnd 01 Date Standard 01: 8.PS2.1 Magnetism and Electricity Design and conduct investigations depicting the relationship between magnetism and electricity in electromagnets, generators, and electrical motors, emphasizing the factors that increase or diminish the electric current and the magnetic field strength. Science and Engineering Practice(s) Develop and Use Models, Obtain and communicate information, Construct Explanations Crosscutting Concepts Cause and Effect, Systems and Systems Models I Can Statement ...I can explain and demonstrate cause and effect relationships between magnetism and electricity.

Magnetism and Electricity Notes Stnd 01: Magnetism and Electricity Science Magnetic Fields An invisible magnetic field exists around all magnets. N S

You can see the magnetic field lines by using fine iron filings. Magnetic Fields You can see the magnetic field lines by using fine iron filings. Note: field lines are concentrated at the ends (called poles) Note: polarity is the property of having two opposing roles. North Pole South Pole

Magnetism and Electricity Notes Stnd 01: Magnetism and Electricity Science North and South Poles All magnets have these poles regardless of their shape. If you cut a magnet in half, each half will still have these two poles (north and south) Bar magnet Horseshoe Magnet Donut magnet

F.Y.I: Why Are Some Substances Magnetic? All atoms have magnetic fields with north and south poles. Atoms in objects are found in areas called domains. If the poles line up facing the same direction, this makes the object magnetic. If they don’t line up, it is not magnetic.

Magnetism and Electricity Notes Stnd 01: Magnetism and Electricity Science Magnetic Forces magnets exert force on other magnets “Opposites attract” (North & South pull towards each other) N S “Like repels” (North & North or South & South push away) N S

Electromagnets Electric current in the wire produces a magnetic field which lines up atoms in the domains of the iron core forming an electromagnet. Simple Electromagnet Iron Core Source of Electricity Solenoid An electromagnet consists of a solenoid wrapped around an iron core attached to a source of electricity

Electromagnetic Induction Magnets and a coil of wire can induce (generate) electricity This process is called electromagnetic induction Note: another name for electricity is electrical current Note: another name for a coil of wire is a solenoid Simple Electrical Generator Coil of Wire (Solenoid) Bar Magnet

Electromagnetic Induction The magnet has to move through the coil … or the coil has to move through the magnet Simple Electrical Generator Here is the magnet Galvanometer Here is the solenoid (coil of wire) Here is a Galvanometer (measures electric current and direction of the current) Solenoid The bar magnet is pushed back and forth through the solenoid Magnet

How It Works All magnets have an invisible magnetic force field. The bar magnet is pushed back and forth through the solenoid Simple Electrical Generator The magnetic force field pushes the electrons from atom to atom in the wire creating electrical current.

Look at the two generators shown below Generators convert mechanical energy into electrical energy Both diagrams are showing electromagnetic induction. Note: in picture 01 the wire coil is stationary and the magnet is moving back and forth Note: in picture 02 the magnet is stationary and the wire coil is rotating Picture 02 (It works either way) Picture 01

Rotational Generators (very common) Note: the magnet is stationary and the wire coil is rotating. It also works if the wire is stationary and the magnet is moving Rotational Generator Magnet Magnet Wire Coil

F.Y.I.-Electromagnetic Induction …is how most electricity is generated around the world. These power plants all use magnets and coils of wire to make electricity Nuclear Power Plant Wind Turbines Coal Power Plant Hydroelectric Dam

F.Y.I.-Electromagnetic Induction …is how most electricity is generated in cars, trains, boats, & planes Each of these machines has a generator inside that creates electricity Electrical Generator (Alternator) Consists of a magnet rotating through a coil of wire

Two Ways to Increase the Electrical Current (1) Move the magnet faster (2) Add more coils of wire

Brainpop Video Notes Science Stnd 01: Magnetism and Electricity Science Brainpop Video View the video titled "Electromagnetic Induction” Link: Brainpop Website Duration: 2 min 25 sec User name: ----- (ask your teacher for the user name) Password: ----- (ask your teacher for the password) Task 01: Write down five things that catch your attention as you watch this video. Task 02: Complete the Brainpop quiz.