MAGNETISM

MAGNETS - A special ________________ first discovered more than 2000 years ago in Greece, in a region called Magnesia; it attracted _______________; they called it ______________________ hence the magnet name. About 1000 years ago they noticed that a hanging magnet always pointed to the ______________________ or Lodestar. So another name for naturally occurring magnets is ___________________. MAGNETISM is the force of attraction or repulsion ____________________ ______________________________.

MAGNETIC POLES the _____________ of the magnet, area where the magnetic effect is the _______________________. If a bar magnet is suspended by a thread or string, it will align itself so that one strong end points __________________ and the other points ___________________, hence the names for the North and South poles of the magnet. _____________ poles of separate magnets ____________ push away from each other. _______________ poles _______________ each other.

MAGNETISM - The moving electron acts as a mini ________________________ charge and therefore has a _________________________ field associated with it. Groups of atoms with magnetic poles aligned are called _______________________________. Materials with most of the domains _______ ______ are considered magnetized. The ___________ domains that are aligned, the _______________ the magnetic field in the material. When domains are randomly arranged, their forces ______________ each other out and there is no ________ magnetic effect. When domains have their magnetic effect in alignment, their forces are ____________________ and create a _______________ magnetic effect. If you snap a magnet in half, the inside pieces become the ____________________ poles

DRAW NONMAGENTIC DOMAINSDRAW MAGNETIC DOMAINS

A connection between ______________________ and __________________________ was discovered (________________________) over 100 years ago. Hans Christian Oersted discovered in 1820 that an electric current near a compass causes the compass needle to be ____________________. Oersted's experiment showed that every _______________________________ has a _______________________ surrounding it. A magnetic field causes a _________________ to align in the direction of the opposite _________________.

MAGNETIC FIELD - ___________________________ were introduced by Michael Faraday , who named them lines of force. . All magnetic fields originate from ______________________________. A magnetic field is the ____________________ effect of electric currents and magnetic materials. A magnetic field appears only when relative __________________ is present between an electric charge and an observer. Electric and magnetic fields are different aspects of a _________________________ field. A magnetic field is that ________________ around a magnet that is __________________ by the magnet. __________________ at the poles, the force forms ___________________ that go out of the North Pole and _____________________________around to enter in at the South Pole. The Earths core is Iron so Earth is a giant magnet

DRAW THE MAGNETIC FIELD LINES

N S

ELECTROMAGNETISM - An _______________________ consists of an __________ core placed inside a _______________________. The magnetic field strength of a wire coil carrying electric current ____________________ in direct proportion to the _________________ of turns of the coil. Current gives rise to ___________________ fields, just as electric charge gave rise to _________________ fields. The basic idea behind an electromagnet is extremely simple: By running ________________

_____________________ through a wire, you can create a magnetic field. Electricity through the coiled wire creates a magnetic field which ______________ magnetism in the iron core. The ______________ in the core become aligned with the magnetic field of the coil. An electromagnet can be used to move large quantities of _______________. When the current is ________, the magnet will pick up the metal. When you want to drop it, you turn off the ___________________ and the electromagnet is disabled and the metal drops.

ELECTRIC MOTOR - A __________________ electromagnet is used in an electric motor to convert __________________________ energy to ________________________energy. Electric ____________ convert electrical energy to mechanical energy. An __________________________ turns inside of a ______________________ magnet. By changing the ______________________ of the current, the _____________ will keep switching between N and S, and therefore cause the electromagnet to continually _________________. Electric motors are used in most household ____________________ which convert electricity into ___________________.

ELECTROMAGNETIC INDUCTION - When a magnet is moved near a __________________, an electric current can be _____________________. This process is called electromagnetic _____________________. The ___________________ of the induced current can be ______________ by reversing the _______________ of the wire or reversing the ________________ direction. The ______________________ of the current depends on the _______________________ of the magnetic field and the _______________ of the wire's motion. This is the basis for electric generators.

ELECTRIC GENERATOR - Electromagnetic induction is used in the operation of a _____________, a device that converts ______________________ energy to _____________________ energy. In a generator, an electric current is produced when a coil of wire is ________________________________ in a __________________ field.

LABEL EACH AND GIVE ENERGY TRANFORMATIONS

_______________________________________________________________

USES OF ELECTROMAGNETISM

MRI - The use of ____________________ waves to make pictures of the _________________ of the body. Using a large magnet, radio waves, and a computer, a _________________________________ ___________, or MRI, produces _________-dimensional and _______________-dimensional pictures.

TRANSFORMER - A transformer is a device composed of two ____________________ coils, usually wrapped around a soft _______________ core, that can increase or decrease the __________________ of AC current. A transformer is used to step the voltage _____________ and the current ___________ (P=IV) so that we can use it. __________ power is desired for the transport of electricity over ________ distances to avoid _______________ of energy to heat loss.

MICROPHONE - A moving coil activated by _______________________________ is used as a microphone. The coil induces a current in the magnet that can be _____________________ or ______________________.

MAGLEV TRAIN - The experimental Japanese Maglev train uses magnetic forces for both _______________ and ____________________. It is a _________________________________ (maglev) railway system based on the principle of magnetic _________________________ between the track and the cars. In April 2015, a manned seven-car Maglev train reached a speed of 603km/h (375mph).

AURORA - An Aurora is an _______________________ discharge through the atmosphere connected with _____________________ disturbance. Most aurora are ___________ and __________ emission from atomic oxygen. Molecular nitrogen and nitrogen ions produce some low level red and very high _______________________ aurora. Northern Hemisphere: aurora _____________________; Southern Hemisphere: aurora _____________________