P7- motor effect Flashcards
what is the motor effect?
wire carring current placed in a magnetic field will experience a force, CURRENT must be PERPENDICULAR to magnetic field>
how is force created when a current carrying wire is in a magnetic field? what does it lead to? (1 word)
magnetic field around the wire INTERACTS with the magnetic field of the magnet causing a FORCE to act on wire, causing MOVEMENT!
how do you increase force + motor effect
BIL:
incr current/PD (I)
incr strength of magnetic flux dens (B)
incr leng of wire (L)
What is unit for magnetic flux density?
tesla (T)
how do you find out the direction of force ?
FLEMMING’s left hand rule
in flemming L hand rule, what does your thumb represent?
FORCE (motion)
in flemming L hand rule, what does your POINTY (second) finger represent?
direction of MAGNETIC FIELD
in flemming L hand rule, what does your middle finger represent?
CURRENT
what does flemming L hand rule represent?
if you reverse current or magnetic field, then direction of force is reversed
why does the coil in a motor rotate?
WHY?
the force on either side of the coil acts in opposite directions, because current is flowing in opposite directions on each side of the COIL
what is a split ring commutator? what does it do?
reverses the current every half-turn of the coil, so the loop rotates continuously in the same direction.
how do you increase the speed of the motor?
increase current, adding more turns to the coil or increasing the magnetic flux density
