Mod 7 review

Question 1

Magnetism

Answer 1

refers to the properties and interactions of magnets

Question 2

Magnetic force

Answer 2

a force that can either attract or repel.

Question 3

Strength of the force between two magnets does what when the magnets move closer?

Answer 3

Increases

Question 4

Strength of the force between two magnets does what when the magnets move away from eachother

Answer 4

Decreases

Question 5

Magnetic field

Answer 5

is a region of space that surrounds a magnet and exerts a force on other magnets and objects made of magnetic materials

Question 6

Magnetic forces are strong or not very strong?

Answer 6

Not very strong

Question 7

True or False Magnetic forces have range?

Answer 7

True

Question 8

-Magnetic fields can be represented by lines of force called what?

Answer 8

Magnetic field lines

Question 9

Magnetic fields are closer or father apart from when close to the magnet?

Answer 9

Closer

Question 10

True or False
Magnetic field liine do not show magnetic fields

Answer 10

(False) They do show magnetic field lines.

Question 11

Magnetic field run North to South or South to North?

Answer 11

North to South

Question 12

What are the magnetic elements?

Answer 12

Iron, cobalt, nickel,

Question 13

Why do some magnetic things not behave like magnets?

Answer 13

Because the poles of the domain are arranged randomly and point different directions. So everything cancels out.

Question 14

What happens if you place a nail in a magnetic field many of the domains align in the magnetic field?

Answer 14

The poles of many domains point in the same direction and no longer cancel each other out, and act like a magnet.

Question 15

Permanent magnets

Answer 15

any magnet whose domains remain aligned without an external field.

Question 16

True or False?
100% of domains will never be aligned.

Answer 16

True

Question 17

True or False
Permanents can be made by stiking a magnetic material with another permanent magnet.

Answer 17

True

Question 18

True or False
The less coils the strong the electric field is.

Answer 18

False, The more coils the strong the electric field is.

Question 19

Electromagnetic force

Answer 19

is the attractive or repulsive force between electric charges and magnets.

Question 20

Electromagnetism

Answer 20

the interaction between electric charges and magnets.

Question 21

True or False
Electromagnetic force is stronger than gravity.

Answer 21

True

Question 22

True or False
Gravity only repels and electromagnetic forces only attrack

Answer 22

(False) Gravity only attracts and electromagnetic forces only repel.

Question 23

Solenoid

Answer 23

A single wire wrapped into a cylindrical wire coil.

Question 24

Electromagnet

Answer 24

is a temporary magnet created when there is a current in a wire coil.

Question 25

True or False Electromagnets are only magnets when there is a current

Answer 25

True

Question 26

Galvanometer

Answer 26

is a device that uses an electromagnet to measure electric current.

Question 27

Electric motor

Answer 27

is a device that changes electrical energy into mechanical energy.

Question 28

Electromagnetic induction

Answer 28

Is the generation of an electric current by changing a magnetic field.

Question 29

Generator

Answer 29

uses electromagnetic induction to transform mechanical energy into electrical energy.

Question 30

Turbine

Answer 30

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

Question 31

Direct current

Answer 31

is electric current that is always in one direction through a wire.

Question 32

Examples of Direct current

Answer 32

Battery powered things: Radio, Remote, RC Car, etc.

Question 33

Alternating current

Answer 33

is electric current that reverses the direction in a regular pattern.

Question 34

Examples of Alternating current

Answer 34

Wall outlet is a alternating current: pencil sharpener, Lamp, Step-up and Step-down transformers etc.

Question 35

Transformer

Answer 35

is a device that increases or decreases the voltage of an alternating current.

Question 36

Types of transformers

Answer 36

Step-up and step-down transformers (look in the book)

Question 37

How does a permant magnet turn mechanical energy into electrical energy

Answer 37

Permanent magnet spin attracts magnets to the north end and repels them from the south pole causing them to move which causes electricity.

Question 38

How does electricity create an electric field

Answer 38

by moving electric charges it generates a field.

Question 39

What does a Magnetometer do?

Answer 39

detects magnetic fields.

Question 40

Atoms in magnetic fields do what?

Answer 40

They behave like magnets.

Question 41

Moving electric charges, such as currents, are surrounded by what?

Answer 41

magnetic fields

Question 42

Finish the Phrase In a simple electric motor_____________

Answer 42

An electromagnet rotates between the poles of a permanent magnet.

Question 43

Explain why a bar magnet will attract an iron nail to either its north pole or its south pole, but it will attract another magnet to only one of its poles.

Answer 43

It repels a magentic of the same kind, but the Iron Nails Pole will aline to the pole.

Question 44

A student connects a battery to the primary coil of a step-up transformer in order to boost the voltage. Explain why a small electric motor does not spin when it is connected to the secondary coil of the transformer.

Answer 44

A Battery is DC, but a transformer need AC to work.

Question 45

A step-up transformer does what to voltage?

Answer 45

increases voltage with more turns in the secondary coil.

Question 46

A step-down transformer does what to voltage?

Answer 46

decreases voltage with fewer turns in the secondary coil.

Question 47

Groups of atoms with aligned magnetic poles are called

Answer 47

Magnetic domains

Question 48

Explain why a magnet sitting next to a wire does not induce a current in the wire

Answer 48

A magnet next to a wire won't induce a current because the magnetic field needs to change over time. If the magnet is stationary, the field stays constant, and no current is produced.

Question 49

Atoms at the north pole of a magnet have

Answer 49

Only North Magnetic Poles