BJU Physical Science Chapter 20 (6th edition), BJU Physical Science (6th ed) - Chapter 21

north pole of a magnet

the pole from which the magnetic field lines EXIT from a magnet

south pole of a magnet

the pole into which the magnetic field lines ENTER a magnet

what kind of force (repulsive or attractive) is represented in the diagram?

repulsive

Where does Earth's magnetic field originate?

deep inside the earth

a group of atoms whose magnetic fields are aligned

magnetic domain

a strong magnet's domains will...

be aligned in the same direction

What will most likely happen to the magnetic field of a magnet heated over a flame?

weaken its magnetic field

If all other factors are the same, what would produce the greatest magnetic field when electrified?

an electromagnet

Name two scenarios that result in electromagnetic induction.

1) a bar magnet is moved through a coil

2) a coil of wire is moved in a magnetic field

How do electrical generators produce AC power?

by rotating wire coils within stationary magnetic fields OR by rotating magnetic fields within stationary wire coils

the main difference between AC and DC generators is what?

the DC generator contains a commutator

commutator

A device that controls the direction of the flow of current through an electric motor

For a transformer to produce the highest output voltage, how would it need to be set up?

a higher number of wraps in the output coil than in the input coil

Was magnetism a recent discovery?

no. the Greeks knew about magnetism through magnetic rocks

What will a magnetic north pole attract?

a magnetic south pole

Do opposites attract or repel?

attract

what type of force is magnetism?

field force

What is an interesting fact about the earth's magnetic South Pole?

it is actually a north magnetic pole

Which of the earth's poles are fixed? Which of the earth's poles are changing?

geographic poles are fixed. Magnetic poles are constantly changing location.

What type of materials can become weakly magnetic in the presence of a magnetic field?

non-ferromagnetic materials

When a strong magnet is near non-ferromagnetic material, what can happen?

the creation of temporary magnets

What does flowing current in a wire always produce?

a magnetic field

a magnetic field around a wire can produce a current in the wire ONLY IF...

the magnet is moving

electrical generators convert _______________________ energy into _________________________ energy.

mechanical energy into electrical energy

Motors convert ___________ energy into ________________________________ energy.

electrical energy into rotary mechanical energy

What do electric motors use to cause interaction between the magnetic fields of the magnet and the wire coil's current?

electricity

What type of generator includes a commutator that allows current to flow in only one direction?

DC generator

Can a solenoid induce an electric current in a nearby, unconnected solenoid?

yes.

what types of transformers do electric companies use?

both step-up transformers and step-down transformers

What can induce an electric current in a wire?

a moving magnet AND moving a wire through a magnetic field

a coil of wire that can act as a magnet

solenoid

a group of atoms whose magnetic fields are aligned

magnetic domain

that which limits current flow to only one direction

commutator

an area of concentrated magnetic force

magnetic pole

an electrified wire coil paired with a strong magnet inside

electromagnet

identified by the ancient Greeks as being able to attract metal objects

lodestone

that which increases or decreases the voltage of an AC current

transformer

that which produces electric current using wire coils and a magnetic field

generator

the region surrounding the magnet where it can exert a magnetic force

magnetic field

who observed that an electric current caused a compass needle to move?

Oersted

electromagnetic wave

transmits energy through matter/medium or open space/vacuum

speed of light

electromagnetic waves/radiation travel this fast

prism

used to separate white visible light into the colors of the rainbow

electromagnetic spectrum

the collection of all electromagnetic waves

photons

massless particles that are a bundle of electromagnetic wave energy

wavelength

the distance from crest to crest, trough to trough or any two identical points on a wave

wavelength, frequency and energy

How do we classify electromagnetic waves?

electric and magnetic

What two fields interact to produce an electromagnetic wave?

perpendicular

Are the wave fields in an electromagnetic wave parallel or perpendicular?

transverse waves

What type of wave is an electromagnetic wave that has electric and magnetic fields?

communication, medicine, cooking, telephone

How are electromagnetic waves used?

radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, gamma rays

Rank the types of electromagnetic waves from lowest frequency to highest frequency.

photoelectric effect

the emission of electrons when electromagnetic radiation, such as light, hits a material

wave-particle duality

the current model of light which explains that the behavior of electromagnetic energy travels as both particles and waves

radio wave

the longest wavelength that is converted into sound and pictures

microwaves

absorbed into water molecules to increase the temperature of food

infrared waves

third on the electromagnetic spectrum that produces heat for reptiles, plants and other animals

visible light

the only light that humans can see and is detected in color (ROYGBIV)

ultraviolet light

requires sunscreen to protect our skin and is utilized by bees to detect flowers

x-rays

these rays are blocked by bones to produce pictures

gamma rays

extreme high frequency waves that are emitted during a nuclear explosion or by radioactive materials

Albert Michelson

Who discovered the speed of light?

Heinrich Hertz & C. Huygens

Who discovered the Particle Model?

What waves are between infrared and ultraviolet?

visible light

What has slightly lower frequency than microwaves?

radio and TV waves