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Andy Halpern
Science Study Guide
Magnets
The Nature of Magnetism
(sectione one)
Vocab:
a. Magnetic Poles- A pole is the area of a magnet where the magnetic effect is strongest.
b. Magnetic Field- A magnetic field is the force exerted in the religion around a magnet
c. Magnetic Field Lines- The magnetic field lines map out the magnetic field.
d. Atom- an atom is the smallest particle of an element, that has all the properties of that element.
e. Element- an element is one of 100 basic materials that make up all matter.
f. Nucleus- the nucleus is in the center of an atom.
g. Proton- a proton is a kind of nuclear partice that has a positive charge.
H. Electron- an electron is something that orbits around the nucleus.
I. Ferromagnetic Material- a ferromagnetic material is a matieral that can be magnetized( something with Magnetitize, Lodestone,or Hypnostone)
J. Permanent Magnet- a magnet made of material that keeps its magnetism
K. Magnetism- Magnetism is the attraction of a magnet and iron.
Section Summary-
Magnetism the attraction of a magnet for iron. All magnets have 2 poles, the North and the South. When you put two magnets together, two poles that are alike repel, while Opposites attract. Each magnet has a magnetic field which is the area the magnetism is exerted. The magnetic field is drawn out by magnetic field lines that curve from one of the magnet to the other. All things are made out of atoms. In the center of the atom is a nucleus that is made up of protons neutrons and electrons. Neutrons have no charge, protons have a positive charge and electrons carry a negative charge. In magnetic objects, the electrons spin around the nucleus. The spinning is what causes the magnetic pull. In magnetic materials all the atoms are lined in the same way to make up magnetic domains. To make something a magnet, all of it's domains or most of them need to be lined up in the same direction. Something that can be magnetized is a ferromagnetic material. When a strong magnetic field is put near a ferromagnetic object it can be made into a temporary or permanent magnet depending on the matieral and the strength of the field. A permanent magnet keeps its magnetism for a while. You can weaken the magnetism by dropping a magnet or heating it.
Here are the Two magnets, N-S= poles, the two poles are opposite, therefore they attract.
Magnetic Earth
(section 2)
Vocab:
1. Compass- a compass is a device that ahs a magnetized needle that can spin freely.
2. Magnetic declination- the angle bwteen geographic north and the north to which a compass points( magnetic north )
3. Solar Wind- stream of electrically charged particles flowing at high speeds from the sun.
4. Magnetosphere- region of earths magnetic field confined by the solar wind.
5. Aurora- a glowing region caused by the charged particles from the sun.
Explanation-
Earth is a magnet because of the iron and nickel in the earth's core. A compass points north because the magnetic field of earth and it's line up, so that it points to the North Pole.
The geographic north pole is different from the magnetic north pole. The difference is called Magnetic Declination.
Earth's magnetic field is called the magnetosphere. It is made up from solar wind from the sun. Some solar wind makes it into earth's atmosphere and is attracted to the poles When they reach earth they glow and are called aurora.
When ferromagnetic objects are left on earth for a long time, they become magnetized because the earth is a magnet.
Scientists can observe the eccects of earth's magnetic field by the rock at the mid ocean ridge. They have iron so the domains of the rock line up with earth's magnetic domains. When the rocks cool, they harden and make magnetic stripes on the ocean floor. Every one million years, the direction changes.
Here is a picture of earht as a magnet; it also is an example of the magnetic fields. The magnetic field lines go from one pole to the other.
Electricity and Magnetism
(section 3)
Vocab:
l. Electric Charge- a property of electrons and protons. Electrons carry a negative charge and protons carry a positive charge.
m. Electric Current- electric current is the flow of charge through a matieral.
N. Electric Circuit- an electric circuit is a compltete path through which electric charges can flow.
o. Conductor- a conductor is what electirc currents can flow freely through.
p. Insulators- insulators are a differnet kind of material in which electric charges and currents can't move through freely.
Q. resistor- a resistor uses electrical energy as it interferes with, or resists the flow of charge. \
R. resistance- the opposition of charges flowing through a material is called resistance.
S. Superconductor- a superconductor is a material that as no electrical resistance.
Explanation-
-Oerstad discovered electrical magnetism.
Steps
#1. Electric charge inside electric current travels from the power source( ex. battery) to the switch.
#2. The switch is connected to the resistor, and once turned on the electric currents flow, when turened off the electric currents are held.
#3. The electric current travels to the resistor( ex: light bulb ) The resistor takes some energy and sends the rest back.
#4. The rest of the energy goes back to the source and starts the process over again
The electric current causes the magnetc field.
Power Source, to switch, and lightbulb
Conductors= copper,silver,iron,aluminum
Insulator- plastic, wood, rubber, glass, sand
The resistance is the object that is using the electric charge such as a lightbulb.
Electromagnets
(section four)
Vocab:
1. Solenoid- a coil of wire with many loops that carries electric currents.
2. Electromagnet- a solenoid with a ferromagnetic object inside.
Explain:
A current-carrying wire can be twisted into many loops. The result of this is it gets a strong magnetic field in the center. The two ends are equivalent to poles. The more loops the stronger the magnetic field gets. When you put a ferromagnetic object inside those coils, it becoems an electromagnet. An electromagnet is a strong magnet that can be turned on and off. You can make it more powerful by adding more coils, making them close together, strength of source, strength of ferromagnetic material.
Here is a picture of an electromagnet. A ferromagnetic object, nail. Inside a solenoid.
QUIZ
1. How do magnetic poles interact?
2. What is the shape of the magnetic lines of force?
3. How are domains of a magnet arranged?
4. Whats the earth's magnetic field called?
5. What is Magnetic Declination.
6. WHat can earth do to ferromagnetic objects lying there for a while?
7. How does the mid-ocean ridge effect magnetic field observation?
8. How is electric current related to a magnetic field.
9. How are conductors differnet from insulators?
10. What are the characteristics of an electric circuit?
11. What are the characteristics of an electromagnet?
Answers:
1. Magnetic poles that are alike repel and magnetic poles that are opposites, attract.
2. The shape of the magnetic field lines are semi circles that go from one pole to the other.
3. The domains opf a magnet are all lined up the same direction.
4. Earths magnetic field is called the magnetosphere.
5. Magnetic declination is the difference between the geographic and magnetic poles.
6. Earth can magnetize those objects.
7. Mid Ocean ridges effect magnetic field observation because the magnetic domains dry in the same direction as earth's magnetic field.
8. Electric current is related to magnetic field because the electric current creates a magnetic field around it. Oerstad discovered this.
9. Conductors allow electric charge to move freely while insulators have resistance.
10. An electric circuit consists of: wires, a power source, a resistor, and a switch.
11. An electromagnet consists of, a solenoid, a ferromagnetic object, wires, a switch, and a power source.
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