PHYSICS - electromagnets Flashcards
When an electric current flows what does it create ???
Magnetic Field
How do you strengthen the magnetic field ???
1) By wrapping the coil around an iron core
2) Adding more turns to the coils
3) Increasing the current flowing through the coil
how are electromagnets different to bar magnets?
electromagnets can get turned on and off using a switch however bar magnets are permanent
what is a relay?
an electricity operated switch
when is a voltage produced?
when a magnet moves into a coil of wire
what is electromagnet induction?
a process where a conductor placed in a changing magnetic field causes the production of a voltage across the conductor
name 3 things to increase induced voltage
1) move the magnet faster
2) add more turns to the coil
3) increase the strength of the magnet
when is a magnetic field created?
when an electric current moves through a coil wire
what can plotting compasses be used to show?
the shape and direction of the magnetic field created by a coil of wire
what is a solenoid?
a long thin spiral of wire used to produce a magnetic field
what is the motor effect?
a current carrying wire or coil exerting force on a permanent magnet
how can an electric motor be built?
using a coil of wire that is free to rotate between two opposite magnetic poles
what do speakers contain?
both an electromagnet and a permanent magnet
what do speakers contain both of?
a permanent magnet and an electromagnet
