6.3 Flashcards
Magnetic field
Region around a permanent or a moving charge in which a body with magnetic properties will feel a force
The field lines show the direction a plotting compass would point
Magnetic flux
The product of magnetic flux density and the area at right angles to the flux
Measured in Webber’s
Magnetic flux density
(Magnetic field strength) defined as the product of the force on a length of current carrying wire
Units Tesla
webber
unit of magnetic flux when one Tesla passes at right angles through an area of one square meter
fleming’s left hand rule
shows the direction of the force on a conductor carrying a current in a magnetic field, thumb=force, first finger=field,second=current
velocity selector
is a device using perpendicular magnetic and electric fields to select charged particles travelling at a specific velocity
electromagnetic induction
the process of inducing an emf in a conductor when there is a change in magnetic flux linkage across the the conductor
induced emf
the emf produced by electromagnetic induction
magnetic flux linkage
for a coil equals the product of the magnetic flux through the coil and the number of the turns on the coil
faradays law
the magnitude of the the induced emf is equal to the rate of change of the flux linkage
lenzs law
the direction of any induced emf or current is in a direction that opposes the flux change that causes it
search coil
small flat coil used to determine the strength of a magnetic field
generator
device used to generate electricity in which the work done to turn the coil in the magnetic field is transferred to electrical energy . The rotation of a coil within a magnetic field produces a constantly changing flux linkage in the coil. This in turn produces a constantly changing emf
alternating current
electrical current that reverses its direction with a constant frequency
transformer
a device that can either incense or decrease the size of an alternating voltage with little power loss
