magnetism Flashcards
what are the names of the two magnetic poles
north and south
what are the 4 magnetic materials
iron cobalt nickel and steel
what happens if two north poles are placed near each other
they repel each other
what happens if a north and south pole are placed near each other
they attract each other
where around a magnet is the field the strongest
at the poles
how can you tell by looking at a diagram of a magnetic field its strength varies at different positions
the magnetic field lines will be closer together where it is stronger and further apart where it is weaker
how can we see magnetic fields
either using iron filings or plotting compasses around the magnet
what is the difference between a magnet and a magnetic material
magnetic materials are always attracted to magnets but magnets can repel or attract each other
what is the effect on a current carrying wire in a magnetic field
the motor effect ( the wire will experience a force perpendicular to both the current and the field
how can you increase the size of the force on the wire
increase the current
increase the magnetic field
increase the length of wire
wrap the wire into a solenoid shape (coil)
what happens if the direction of the current is flipped
the direction of force will flip too
what happens if the direction of the magnetic field is flipped
the direction of the force will flip too
what happens if both the current and magnetic field are flipped
the direction of force stays the same
what is Fleming’s left hand rule
it links the direction of force (thumb) magnetic field (index/ first finger) and current (second finger)
what can we use to predict the direction of field around a wire
the right hand grip rule. thumb for direction of current fingers for field
what is the difference between a permanent magnet and an induced magnet
permanent magnets have their own magnetic field, whereas induced magnets becomes magnetic when placed in a magnetic field but looses its magnetism when removed from the field
what happens to the strength of a magnetic field further away from the magnet
it becomes weaker
what direction is a magnetic field
from north to south ( where would a north pole be attracted to)
why do compasses all point in the same direction
the Earth has a magnetic field
what causes the Earth magnetic field
the currents within the Earths outer core (molten Iron and Nickle)
what is the field inside a solenoid like
strong and uniform
what is the unit for measuring magnetic field strength (flux)
teslas
explain why a motor rotates
the current flowing through the coil will pass one way on one side of the coil and back in the opposite direction on the other side, as the direction of current is opposite so will the direction of forces on the wire, making it rotate.
