Acadeca Science Section 3: Magnetism

The ends of magnets are labeled as

north and south poles

The fundamental unit of magnetism is called a

Magnetic Dipole

No one has seen evidence of

Magnetic Monopole

A standard bar magnet has a north and south pole, with the magnetic field lines

come out of the north and back into the south

Ferromagnetic

Materials that when exposed to a strong magnetic field, their atoms line up and make a permanent magnet

Paramagnetic

Materials that become magnetized when exposed to a magnetic field BUT the magnetism goes away when the field goes away

Magnetic fields are produced by

electrically charged particles

Magnetic fields are only produced when

particles are moving

Who observed “a wire with a current running through it would deflect a compass” and in what year

Hans Christian Oersted, 1820

Oersteds observation was the first deeper connection between

Electricity and Magnetism

Motion is also required for charged particles to

feel magnetic forces

The magnetic field generated by a moving charges always points…to the direction in which the charge is…

perpendicular, moving

The magnetic force is/is not…

IS NOT, fundamental

Magnet originates from…where…-attracting lodestones were found

Magnesia, Greece. Iron

Compasses point…due to Earth's…

North, Magnetic Field

The…pole of a compass is attracted to Earths…

north, south magnetic pole

Earths magnetic field reverses…

polarity

As the sun rotates, its magnetic field can get…by the…

twisted, rotating plasma

Cool, dark spots on the sun are called

Sunspots

Coronal Mass Ejection

Chunks of the sun getting ejected due to an overly twisted magnetic field

When solar winds enter the atmosphere, they break apart…and turn into…, These ions capture…and emit colors of light, known as Aurora’s

atoms, ions, electrons

Oxygen tends to glow…and hydrogen…

Green, Purple

Spacecraft have found that the planets…also have a…

Jupiter and Saturn, Strong magnetic field

The most extreme magnetic fields in nature come from

Neutron Stars

B is the strength of

The magnetic field, measured in Teslas

The strength of Earths magnetic field ranges from…-… microTeslas

25-60

The direction of the magnetic force is…to the magnetic field

Perpendicular

The magnetic force causes particles to move in a

circle

Centripetal force

Force that does not change the speed of an object but only the direction

What is a mass spectrometer used for

To find the atomic composition of an unknown sample

Who discovered the electron and when

J.J Thomson in 1897

Solenoid

Multiple circular loops on top of each other

An MRI machine can generate currents up to

1-2 teslas

The fact that you can not use a steady magnet to generate current and you need a changing magnetic field was discovered by

Michael Faraday, 1831

After listening to many lectures by…Faraday became his…

Humphrey Davy

Generator

Any device that converts mechanical motion into electrical energy

Motor

Any device that converts electrical energy into mechanical motion

The magnetic field created by the solenoid will be whatever it needs to be to

oppose the external change

The voltage in a wall outlet is equal to

120 volts

A transformer can only be used with an

Alternating Current (AC)

AC can be used when a device is

plugged into a wall

Most devices have something called a

Diode

What does a Diode do

allows current to flow through it in one direction

The amount of voltage you get from an AC varies, When the loop is…you get…, when the loop is….you get…

perpendicular to the field/maximum flux. Parallel to the field/zero flux

Inductor

A solenoid attached to each end of a circuit, resisting changes in current

Who invented the barometric light, when and how was it used

Frank Hauksbee, 1805, it was shaken and mercury rained inside the glass, creating light

Who invented the Arc lamp and when

Humphrey Davy, 1802-1809. It was widespread through the 1860s

In 1891, who invented what

Mikhail Dobrovolsky, the 3 phase generator

Who adopted the 3 phase generator along with what

George Westinghouse with his AC lights

In 1904, what was created by who

The tungsten light bulb by Alexander Just and Franjo Hanaman

What did Tesla love to talk about (3 things)

Himself, infinite energy and communication with martians

What did Tesla actually invent

The Tesla coil