* 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

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

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.

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

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.

oxide of iron

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

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

lines of a magnetic field

degree to which a material can be magnetized is called this

magnet used in an MRI system

good example of a natural magnet

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

Electricity and Magnetism were viewed as separate effects until the?

where output of electricity happens

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

will create a magnetic field perpendicular to that particles motion.

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

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

each zinc copper pile

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

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

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

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

will create a magnetic field along its axis of spin.

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.

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.

Types of Artificially induced permanent magnets

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

* 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

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.

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.

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

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

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

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

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.

Sl unit of magnetic field strength

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

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

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

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

electric potential is measured in units of joule per coulomb

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

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

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.

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

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

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

where input of electricity happens

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).

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

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.

magnetic state that cannot be artificially magnetized

2 Types of Naturally Occurring Magnets

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

magnetic state unaffected by magnetic field

The accumulation of many atomic magnets with their dipoles aligned

1 Tesla is equivalent to?

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

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.

conventional unit of magnetic field strength

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)