electromagnets Flashcards
what is electromagnetism
when a current flows through a wire it creates a magnetic field around a wire
what are 3 ways of increasing electromagnet strength
wind more coils
use a higher voltage
insert a magnetic core
how to determine direction of magnetic field of a wire
using your RIGHT HAND point your thumb in the direction of the wire and the direction of your fingers will determine direction of magnetic field
shape of flat coil magnetic field
shape of solenoid magnetic field
shape of long wire magnetic field
direction of north and south poles of magnetic fields
what is does fleming’s left hand rule look like
how does FLHR work
- a current through a wire creates a magnetic field
- if the wire is already in a magnetic field, they will interact
- a force will act of the wire
- causing it to move - thumb
what is induction
when a wire cuts a magnetic field line
what happens when wire moves parallel to magnetic field lines
no voltage is induced
how to increase current produced during induction
- up the strength of MF
- up numbers of wires being cut
- increase speed of movement or rotation
how do transformers work
- passing a magnetic field between 2 coils
- the primary coil creates an alternating magnetic field as is connected to a.c supply
- the alternating magnetic field interacts with secondary coil
- creates voltage by induced charge
what does a step up transformer look like
relationship between power lost and resistance
power lost in transmission is proportional to resistance
