magnetism transformers Flashcards
In the motor effect what kind of current is used
direct current.
microphone explained
sound waves cause flap to vibrate
coil cuts magnetic field lines
as its a complete circuit it inducs a current
coild vibrates field lines cut in opposite direction
so makes an ac
louspeaker effect
current produces a magnetic field which interacts with the magnetic field of a magnet
produces a force
current is alternating so produces an ac
causes coil and coin to vibrate
causes air particles to vibrate causing a longditudinal sound wave.
motor effect 3 marker
magnet and current exert a field
they interact
this produces a force.
induced mototr effect
wire cuts magnetic field lines
inducing a voltage
if fully connected circuit then also a current induced.
how does a transformer work
steps up or down a voltage
an ac in primary coil produces an magnetic field.
core becomes magnetised and producess an alternating magnetic field.
coil cuts magnetic field lines inducing a voltage in the secondary coil.
what is a step up transformer
increase voltage decrease current
when thepoer reached home what happens with transformers.
step down transformers so that energy is safe.
how do you measure the magnetic field lines.
put a compass on the north pole mark the point where it points to north move your compass to the point once again mark it do so until it reaches the south pole
advantages of a curved magnet
force is increased
radial magnetic field
coil remains in field for a long time
what is a split ring commutator
reversing the direction of the magnetic field
How does a loudspeaker work
ac current, this causes the force on the coil to be exerted in opposite direcitons and make it move back and forth. These cause the cone to vibrate in different directions.
what does a transfomer do
change the voltage of an alternating current,
describe different soft or hard materials
iron is a hard material
steel is a soft material
