science

Question 1

something that attracts iron

Answer 1

magnet

Question 2

region at each end of a magnet where the external magnetic field is strongest

Answer 2

magnetic poles

Question 3

attraction or repulsion that arises between electrically charged particles because of their motion.

Answer 3

magnetic force

Question 4

a substance that exhibits ferromagnetic or ferrimagnetic properties

Answer 4

magnetic material

Question 5

physical phenomenon in which certain electrically uncharged materials strongly attract others.

Answer 5

ferromagnetic element

Question 6

a region within a magnetic material in which the magnetization is in a uniform direction.

Answer 6

magnetic domain

Question 7

a magnet made of soft iron, that is usually easy to magnetize;

Answer 7

temporary magnet

Question 8

a type of magnet that retains its magnetic properties indefinitely, even after removing the external magnetic field.

Answer 8

permanent magnet

Question 9

An electromagnet is a type of magnet in which the magnetic field is produced by an electric current.

Answer 9

electromagnet

Question 10

An electric motor is a machine that converts electrical energy into mechanical energy

Answer 10

electric motor

Question 11

any machine that converts mechanical energy to electricity for transmission and distribution over power lines to domestic, commercial, and industrial customers.

Answer 11

electric generator

Question 12

Direct current is one-directional flow of electric charge. An electrochemical cell is a prime example of DC power.

Answer 12

direct current

Question 13

Alternating Current (AC) is a type of electrical current, in which the direction of the flow of electrons switches back and forth at regular intervals or cycles

Answer 13

alternating current

Question 14

a machine that plays a key role in transforming fluid or air energy into usable work or electricity.

Answer 14

turbine

Question 15

transformer, device that transfers electric energy from one alternating-current circuit to one or more other circuits, either increasing (stepping up) or reducing (stepping down) the voltage.

Answer 15

transformer

Question 16

Name some element that are ferromagnetic

Answer 16

Iron, nickel, cobolt

Question 17

As a nail approaches the south pole of a magnet, what happens to its magnetic
domains?

Answer 17

The north poles of the domains point toward the magnet

Question 18

What happens to an object that is made of magnetic materials but is not a magnet when
it comes in contact with a magnet? (consider what happens to its magnetic domain and
its ability to repel or attract other magnetic materials)

Answer 18

Its magnetic domains fall into
alignment and it begins to attract other objects made of magnetic material.

Question 19

How can you make an item that is made of magnetic material become a permanent
magnet instead of a temporary magnet?

Answer 19

You can put it in a very strong
magnetic field.

Question 20

As the electric current through a wire increases, what happens to the magnetic field
around the wire?

Answer 20

It becomes stronger.

Question 21

What do a permanent magnet and an electromagnet have in common?

Answer 21

Both have a north pole and a south pole.

Question 22

Consider an audio speaker. For the electromagnet to attract and then repel the
permanent magnet in the speaker, what has to happen?

Answer 22

The electric current must reverse directions

Question 23

.What is the purpose of a commutator in an electric motor?

Answer 23

It reverses the direction of
the current in the electromagnet to keep the motor spinning.

Question 24

.What makes an electric motor spin?

Answer 24

The permanent magnet and the electromagnet
continuously attract and repel each other.

Question 25

.What conditions are necessary for a magnet inside a wire loop to produce an electric current

Answer 25

The magnet must be in motion.

Question 26

The magnet must be in motion.

Answer 26

The magnet moves inside the coil of the wire and the coil of wire moves through a magnetic field.

Question 27

An electromagnet and a permanent magnet both have a ______ pole and a _____ pole.

Answer 27

north; south

Question 28

When a power plant sends out high voltage electricity for long distance transmission, what is needed to make the electricity usable in houses?

Answer 28

Step-down transformer

Question 29

Which part of electrical transmission increases the voltage for transmission?

Answer 29

Step-up transformer

Question 30

The south pole of a magnet will attract the _______ ________ of another magnet.

Answer 30

north pole

Question 31

What do you get when you break an iron magnet into two pieces?

Answer 31

Two north poles and two south poles

Question 32

. The location of the strongest magnetic field is the magnetic _____________.

Answer 32

poles

Question 33

What is the region around a magnet where the magnetic forces act?

Answer 33

Magnetic field

Question 34

A(n) _________________ can only operate when the current is on.

Answer 34

electromagnet

Question 35

Changing the current changes the __________and_________ of an electromagnet.

Answer 35

strength and direction

Question 36

Name the device that increases or decreases voltage in a power line

Answer 36

transformer

Question 37

What type of current does not reverse direction?

Answer 37

direct current

Question 38

What type of current reverses direction in a regular pattern?

Answer 38

alternating current

Question 39

A boy is watching an old television show about people stranded on an island. One of the characters wanted to make an electric generator out of a bicycle. What does he need to find?

Answer 39

Two magnets and a coil of wire

Question 40

What type of energy does a power plant need to produce electricity?

Answer 40

Mechanical energy

Question 41

What kind of energy are you providing as you turn the crank on a simple electric generator?

Answer 41

Mechanical energy

Question 42

An electric generator can produce current that changes direction in a regular pattern. Identify this type of current.

Answer 42

Alternating current

Question 43

Explain what makes the material in a paperclip a magnetic material without it actually being a magnet. Why does the paperclip become a magnet when touching a magnet?

Answer 43

All atoms have magnetic fields made by the movement of the charged particles that make up the atom. When groups of atoms are lined up so that their poles are facing the same direction, this is called a magnetic domain. Magnetic material like that in a paperclip has many magnetic domains, but each domain can point in a different direction. In a magnet, all the domains point in the same direction. When the paperclip approaches a magnet, all of the domains line up according to the polarity of the magnet. Since the domains are all aligned, the paperclip becomes a magnet as well.