discovered in Magnesia (West Turkey) - difficult to detect and measure - exists when there is a charged particle in motion

oxide of iron

rodlike stone that when suspended by a string would rotate back and forth

of a charged particle is perpendicular to its motion - also created when electric current/electrons is conducted through the wire - its intensity is proportional to the electric current - intensity is greatly increased by an iron core - Any charge in motion induces this

motion of electrons rotating in a clockwise or counterclockwise axis - creates a magnetic field which is neutralized in electron pairs

lines of a magnetic field

Atoms with this number of electrons in any shell exhibit a very small magnetic field

created by protons spinning on its axis that creates a magnetic dipole, basis for MRI

The accumulation of many atomic magnets with their dipoles aligned

When all magnetic domains in an object are aligned, it acts like a what?

in its normal state, magnetic domains are distributed in what way?

ability of a material to attract the lines of magnetic field intensity

When an external force acts on the magnetic domains, randomly oriented dipoles do what with the magnetic field?

good example of a natural magnet

2 Types of Naturally Occurring Magnets

Types of Artificially induced permanent magnets

* Consist of wire wrapped around an iron core * current-carrying coil of wire wrapped around an iron core which intensifies the induced magnetic field

magnetic state that cannot be artificially magnetized

magnetic state that can be magnetized by exposure to a magnetic field.

magnetic state that is slightly attracted to magnet and loosely influenced by an external magnetic field. Contrast agents used in MRI.

magnetic state unaffected by magnetic field

degree to which a material can be magnetized is called this

the ends of a magnet and are in pairs; the north and south pole.the ends of a magnet and are in pairs; the north and south pole.

will create a magnetic field along its axis of spin.

will create a magnetic field perpendicular to that particles motion.

some materials such as ferromagnetic materials can be made magnetic by this

imaginary lines of the magnetic field and its density is proportional to the intensity of the magnetic field

who said this - Set out to show that electricity and magnetism are related. - Moving or spinning electric charges should induce a magnetic field. - Used an electric circuit and a compass to prove his experiment.

who said this * 1st law of magnetic induction * An electric current is created in a circuit if some part of that circuit is in a changing magnetic field. * His experiments shows that magnetic fields can create electric currents * He showed the lines of a magnetic field by sprinkling iron filings on a piece of paper covering a magnet.

who said this? * 2nd law of magnetic induction * An induced current within a conductive coil produces a magnetic field to oppose the change in magnetic field which produced it

Who said this? * Proposed that if a changing magnetic field can induce an electric field, then a changing electric field should induce a magnetic field * Changing fields should move at a speed equal to the speed of light. * The magnetic force is proportional to the product of the magnetic pole strengths divided by the square of the distance between them.

Sl unit of magnetic field strength

conventional unit of magnetic field strength

magnet used in an MRI system

1 Tesla is equivalent to?

The Earth's magnetic field is approximately what at the equator

The Earth's magnetic field is approximately what at the poles

Electricity and Magnetism were viewed as separate effects until the?

observed that a dissected frog leg twitched when touched by two different metals as if it had been touched by two different metals (late 1700s).

who said this - questioned whether an electric current might be produced when two different metals are made into contact. - He succeeded in producing a feeble electric current using zinc and copper plates. - stacked the copper-zinc plates to form a Voltaic pile to increase the current.

each zinc copper pile

what is precursor to the modern battery - paved the way to the creation of modern batteries which is an example of sources of electric potential.

modern dry cells use this as the positive electrode surrounded by an electrolytic paste housed in a negative zinc cylindrical can.

electric potential is measured in units of joule per coulomb

The magnetic field produced by an electromagnet is the same as that produced by a bar of magnet

* An electric current is induced in a circuit if some part of that circuit is in a changing magnetic field. * No physical motion is needed. * If the current is increased in the electromagnet, the magnetic field will also change and induce a current in the coil

What law states that the magnitude of the induced current depends on 4 factors: * Strength and the Velocity of the magnetic field as it moves past the conductor * The angle of the conductor in the magnetic field * Number of turns in the conductor

What motor possesses this * An electric current produces a mechanical motion. * Motion of the compass needle. * Has the same components as an electric generator. * Electric energy is supplied to the current loop to produce motion. * Uses many turns of wire for the current loop and many bars of magnets to create an external magnetic field

what motor is this * Mechanical motion induces electricity in a coil of wire. * The motion of a magnet near a coil of wire. * A coil of wire is places in a strong magnetic field between two magnetic poles. * The coil is rotated by mechanical energy which in turn induces an electric current. * The net effect of an electric generator is to convert mechanical energy into electrical energy.

What motor is this * The type of motor used in x-ray tubes. * The rotating rotor is a shaft made of bars of copper and soft iron fabricated into one mass. * The external magnetic field is supplied by several fixed electromagnets called Stators. * Powers the rotating anode of an x-ray tube.

devices that uses the interacting magnetic fields produced by changing electric currents - does not convert but transforms electric potential and current into higher or lower intensity. - Operates in alternating current. - Has a primary turns of wire and a secondary turns of wire

where input of electricity happens

where output of electricity happens

If primary side has less turns of wire than the secondary side, the result will be this

the change in voltage is directly proportional to the ratio of the number of turns (windings) of the secondary coil (Ns) to the number of turns in the primary coil (Np)

as the voltage changes across a transformer, the current changes also.

Transformer that is * Built about a square core of ferromagnetic material. * The ferromagnetic core is not a single piece, but built up of laminated layers of iron. * Helps reduce energy losses, resulting to greater efficiency.

transformer that * Consist of an iron core with only one winding of wire about it. * The single winding acts as the primary and secondary winding. * Connections are made at different points on the coil for both the primary and secondary sides. * Varies both voltage and current. * Generally smaller and its use is restricted to cases in which a small step up or step down in voltage is required. * Not suitable for x-ray imaging.

* Confines even more of the magnetic field lines of the primary winding because the secondary winding is wrapped around it and there are essentially two closed cores. * More efficient than closed-core transformer. * Most currently used transformer

Does not use a ferromagnetic core to link the primary and secondary coils.

Primary and Secondary coils are wound on one cylinder. Magnetic path is partially through the core and partially through the surrounding air

* A current that opposes the magnetic field that induced it creating a loss of transformer efficiency. * Closed-core transformer reduces this

an additional resistance by alternate reversal of the magnetic field caused by alternating current.

* Electric current in the copper wire experience resistance. * Results in heat generation.