co si ch 7 magnets

Each magnetic domain behaves like a single

magnet

Oested correctly hypothesized that an electric current creates a

magnetic field

A magnetic field can be represented by lines of force called

magnetic field lines

A magnetic field exerts a force on other magnets and

magnetic materials

The magnetic force exerted by a magnet is strongest at

magnetic poles

The properties and interaction of magnets are referred to as

magnetism

An electric ____ is a device that changed electrical energy into mechanical energy

motor

When two magnets are brought close to each other, their magnetic fields

overlap

A single wire wrapped into a cylindrical wide coil is called a

solenoid

What happens to the rotation of coil if the current flowing through it is increased?

the coil would rotate faster is the current is increased

Does the figure represent an electric motor or a generator? Explain you answer. (picture)

the figure represent a motor because it is turning electrical energy into mechanical energy. Also it has a power source, wire, and some type of iron, nickel, or cobalt core

A ____ increases or decreases the voltage of an alternating current

transformer

A _____ is a large wheel that rotates when pushed by water, wind, or steam

turbine

Every magnet has ____ poles

two

A transformer has 180 turns in the primary coil and 20 turns in the secondary coil. If the output voltage is 12 V, what is the input V? What kind of transformer is this?

12v (180turns) = 20 v in 2160/20= 108 v step down

"A magnet attracts metals," a friend says. "I disagree. What about aluminum?" Another friend asks. How would you settle their disagreement?

A magnet attracts only magnetic metal. The three magnetic metals are nickel, iron, and cobalt. They are magnetic because they have magnetic domains.

Contrast alternating current and direct current

An alternating current regularly changes and rotates while a direct current stays in one direction.

Is an electromagnet a temporary magnet or a permanent magnet? Explain.

An electromagnet is a temporary magnet because it is only magnetized when it is hooked up to a power source and a current is running through it.

"I know where the magnetic field lines are closest," a friend says, "but I don't know where the magnetic field is the strongest." How would you clear up your friend's confusion?

If you know where the magnetic field lines are closest, that is where the magnetic field is strongest. The closer you are to the magnetic field lines the stronger they are.

"Magnets have to be made in a lab," a friend says. "They don't occur in nature." Do you agree or disagree? Why?

Magnets do occur in nature. That is how they discovered magnetism; people found the first magnetic metal, magnetite, in nature.

What kind of energy is being produced? (picture)

Mechanical Energy

What is structure B? What happens to it when energy flows? (picture)

Structure B is the electromagnet, when it rotates it gives off mechanical energy

"This is the North Pole," a friend says, pointing to one end of a compass needle. "Actually, that's the north-seeking pole," another friend disagrees. How would you resolve their disagreement?

The Earth has a large "magnet" per-say in the center. Our geographical north is the South Pole of the earth's magnet and our geographical south is the magnet's North Pole.

That's the biggest magnet I ever saw!" A friend cries, holding up a large horseshoe magnet. "Not if you ever saw Earth!" Another friend laughs. What is the second friend pointing out?

The Earth has a magnetic field all around it due to the magnetic core of the Earth. There is a circulation of the nickel core molten and that rotates around the solid inner core which creates a magnetic field

What serves as the energy source? What kind of energy does it provide? (picture)

The battery is the energy source and it provides electrical energy

What produces Earth's magnetic field?

The circulation of earth's molten nickel core around its solid inner core.

Magnets can either ____ each other or _____ each other

attract, repel

Groups of atoms with aligned magnetic poles are called magnetic

domain

A compass needle brought near a magnet will line up with the

earths magnetic field

A ____ is a temporary magnet made by wrapping a wire around an iron core

elecromagnet

Electric current can be measured using a

galvanometer

The generation of a current by a changing magnetic field is called electromagnetic

induction