Science Study Guide

Describe the magnetic poles: strength, type

There are two magnetic poles on a magnet: north and south. Their opposite ends attract, and the like ends repel. Their magnetic fields always go from north to south.

What produces the magnetic field around a current-carrying wire? What is a current-carrying wire? What happens to the magnetic field as the electric current increases?

In a current-carrying wire, the magnetic fields of the flowing charges combine to produce a magnetic field around the wire. The magnetic field around a current-carrying wire forms closed circles. Because negatively charged electrons are moving in the wire, the magnet applies a force to the moving charges.

Electromagnet

A coil that has a soft iron core and that acts as a magnet when an electric current is in the coil

Electric motor

A device that converts electrical energy into mechanical energy

Define Magnet

An object that attracts iron

Static Charge

An unbalanced electric charge on an object

What happens to the strength of the magnetic force with distance?

When opposite poles of two magnets are near each other, the resulting magnetic field applies a force of attraction When like poles of two magnets are near each other, the resulting magnetic field applies a force of repulsion.

If two objects have increased charges on them, what happens to the strength of the electrical force? What will happen to the magnitude of the force if the particles get closer together? What happens to magnetic force as magnets move apart from each other?

When two objects have increased charges, the strength of the force will increase. If the particles get closer together, the magntiude of the force on the particles will also increase. As the magnets move apart from each other, their fields seperate.

What type of particles are moving in an electric current? What determines the direction of the force on the wire?

an electric current in a wire produces a magnetic field around the wire. The strength of the magnetic field around a current-carrying wire increases when the wire is wound into a coil.

How are electric motors used in everyday life?

There are electric motors in cars. They make the windows go up and down, they make the windhield wipers move, and so much more.

Define Temporary Magnet

A magnet that quickly loses its magnetism after being removed from a magnetic field

Define Permanent Magnet

A magnet that retains its magnetism even after being removed from a magnetic field

Define Magnetic Pole

A place on a magnet in which the force it exerts is the strongest

Ion

An atom or group of atoms that has a positive or negative charge.

List the steps on how to make an electromagnet.

An electric current in a wire produces a magnetic field around the wire. The strength of the magnetic field around a current-carrying wire can increase when the wire goes into a coil. The magnetic fields around the individual loops of the coil combine, making the magnetic field around the wire stronger.

What is an electric field? Describe the type of force electrical fields can apply to other objects.

An electric field is the region surrounding a charged object. Electric fields can apply a force to another object even if it is not touching that other object.

What is an electromagnet? List 3 ways that an electromagnet is it different from a permanent magnet?

An electromagnet is made by placing a ferromagnetic material, such as iron, as a core within the wire coil. Some of the ways that it is different is that the magnetic field of the coil causes the ferromagnetic core to become a magnet. The core of the electromagnet also can increase the strength of the coil's magnetic field. This makes the electromagnet's force stronger. Andas the number of loops in the coil increases, the magnetci field of the electromagnet becomes stronger.

Electric motors spin. What is making it spin? Discuss the role of the electromagnet, like and unlike poles

Another thing we can do with electromagnets is that the magnetic poles can be reversed. This property of electromagnets is what makes an electric motor spin. When an electric current is supplied to the motor, the unlike poles of the permanent magnet and electromagnet attract each other, causing the motor to begin to turn.

Define Magnetic Material

Any material that a magnet attracts

What is a magnetic material? What is a ferromagnetic material?

Any material that is strongly attracted to a magnet is a magnetic material. Magnetic materials often contain ferromagnetic elements. Ferromagnetic elements are elements, including iron, nickel, and cobalt, that have an especially strong attraction to magnets.

Describe the magnetic fields formed when opposite poles are near each other. Describe them when same poles are near each other.

Both: Both go (always) from north to south. Opposite: The fields attract each other, because they are the opposite poles The same: The like fields repel against each other

. Describe Earth's magnetic field: Why does Earth have a magnetic field (what is causing it?) How does it benefit life on Earth?

Earth has a magnetic filed bevause it has an iron core. It protects the earth and all its living things by repelling charged larticles from the sun.

Contrast Earth's magnetic poles to Earth's geographic poles.

Earth's magnetic poles and geographic poles are not in the same spot. You cannot use a compass for earths geographic poles., you can only use it with the aerths magnetic poles.

List and describe the particles in an atom: name, location, charge

Electron: Negative particles in an atom Proton: Positive particles in an atom Neutron: Neutral (no positive or negative charge) particles in an atom

Negative Charge

Electrons moving around a nucleus have negative charge.

Define Magnetic Element

Elements, including cobalt, iron, and nickel that have an especially strong attraction to magnets

When does a magnetic material behave like a magnet? What has to happen to the magnetic fields of the atoms in the material for it to act as a magnet?

In a magnetic material all the atoms in it form groups called magnetic domains. All the magnetic filed of the atoms have to point the same direction for it to become magnetized.

Neutral

In electricity, this describes an object with no overall electric charge

How can a neutral atom become positively charged? How can it become negatively charged? What are charged atoms called?

It can become positively charged when it loses an electron, and the number (amount) of protons is greater than the number of electrons. It can become negatively charged when it gains an electron, and there are more electrons than protons in an atom. Charged atoms are called ions.

. Why is a compass needle attracted to magnetic fields? Does it always point to the poles? Explain why or why not.

It is attracted to the arths magnetic fields because it is a tiny magnet. It always point to the poles because it is being attracted to them.

Describe how electrically charged objects interact: oppositely charged objects interact in what way? Similarly charged objects interact in what way?

It is somewhat similar to the way charged particles interact with each other. The electric force applied by an object's electric field will either attract or repel other charged objects, depending on if the charge is positive or negative.

How do OBJECTs become electrically charged? What causes an object to become negatively charged? What causes an object to become positively charged?

Objects can become electrically charged because some objects hold electrons more loosely than other objects. So electrons can move from one object to another. When this happens the positive charge and negative charge on the objects are unbalanced. It is negatively charged when some of the electrons transfer over to the object, and the same goes for a positively charged object.

Describe the interaction between charged particles: How do oppositely charged particles interact? How do like-charged particles interact? How do charged particles interact with neutral particles?

Opposite: They are attracted to each other because their poles are different Equal: They repel against each other because their poles are the same Neutral: Neutral objects do not attract or repel against each other

Positive Charge

Protons in the nuclei of atoms have positive charge.

Define Magnetic Domain

Region in a magnetic material in which the magnetic fields of an atom all point in the same direction

Describe the forces between magnetic poles: how do similar poles interact? How do opposite poles interact?

Similar: the like ends repel each other Different: opposite ends atteact each other

Compare and contrast temporary and permanent magnets.

Temporary: the material is only magnetized when it is close to a magnetic filed. Once it leaves, it becomes normal again Permanent: these are always magnetized, even when they are removed from a magnetic field

What is a magnetic field?

The area of magnetic force around a magnet is a magnetic field

What is the charge on an atom? Why (discuss the proton and electron count in relation to each other).

The charge on an atom is neutral, because it has equal amounts of positive and negative charges ( electrons and protons )

Define Magnetic Force

The force that a magnet applies to another magnet

How do magnetic fields and electric currents affect a compass needle? Why?

The compass needle will point in the direction of the field and current because it is being attracted to it because it is a tiny magnet.

Electric current

The continuous flow of electric charges through a material

Describe magnetic field lines: direction, where are they strongest and how can you tell, where are they weakest and how can you tell?

The magnetic filed lines always go from north to south. It is strongest right at the poles, because the magnetic field lines are closer to it. As the magnetic field lines go farther apart, the field and the force become weaker,

What happens to the magnetic domains in a nail when it comes close to a magnet?

The magnetic fileds all begin to pont in the same direction, which is in the direction of the magnet.

What factors affect the magnetic strength of an electromagnet? How can the strength be increased - state two ways.

The size of the core can increase the strength of an electromagnet, and nails can also be used to increase the strength of the elctromagnet.

Electric field

The space around a charged object in which another charged object experiences an electric force

Where is the strongest part of an electrical field?

The strongest part is the core of the electromagnet.

Why are most objects/materials non-magnetic? Talk about the magnetic field of the atoms in most objects.

They are all mostly nonmagnetic because the magnetic field of all the atoms inside the objects and materials dont pint in the same direction; they point in many different and random directions

If you look at iron filings around two un-marked magnets, how could you tell if the magnet poles were north to north or north to south? What would you expect to see in each case with the iron filings? Draw a picture of each scenario.

We can tell because they always go from north to south, and not south to north. The iron fillings would show its filed lines

What two factors affect the strength of the electric force between objects? How does each factor affect the strength of the electric force? Does it increase it or decrease it?

the total amount of charge on both objects and the distance between the objects are the two factors that can affect the strength of an electric force between objects.