Magnetic And Electromagnetic Flashcards
What direction do the magnetic field lines flow?
From north to south
Wharis an electromagnetic?
When current flows through a wire an electromagnetic field is produced. It is temporary. Coil rather than straight wire produces a field like a magnet.
Hoe can you increase thr strength of an electromagnet?
Increase number of coils
Increase current (amps)
Include an iron core
What is an independent variable, dependent variable, control variable ?
Independent - this is the one that the experimenter controls(x axis) eg number of coils
Dependent - this is the outcome of the experiment (y axis) eg nails picked up
Controlled - variables must be kept the same throughout eg current, iron core etc
Why use electromagnetic?
- Scrap metal eg iron and steel
- Tracks of high speed trains
- Relay circuit (relay is a speical type of switch) - powered by coil (circuit 1) to power circuit 2 eg motor, lamp
- Motors - electromagnet field inside a magnet causes a spinning motion to help things move
What is an alloy?
A metal mixture eg steel and carbon
What is a magnet
Iron, nickel or cobalt
They have a north and south pole
Opposite poles attract; like poles repel
Invisible magnetic fields always pointing north to south
Plotting compasses can determine magnetic field lines (n to s)
How does a compass?
Imagine a magnet inside the earth ie compass needle will respond to earths magnetic field. The north pole of the compass points to the magnetic south pole of the earths magnet which is the geographic north of the earth.
