Physics Topic 4

Cards (16)

Magnets can exert force without...
contact
magnetic force can be...
attractive or repulsive
what are the two poles?
North Pole and South Pole
what is the magnetic field?
the space around a magnet in which its force can act
what are magnetic field lines used to represent?
direction of force that would act on a small North Pole at different places in a magnetic field
what do the distances between magnetic field lines show?
the strength of the magnetic field at different places
what is magnetic flux density?
the measure of the strength of a magnetic field at a specific point in the field
what is the unit of magnetic flux density?
Tesla, T
examples of permanent magnets
some iron and steel objects
what is induced magnetism?
objects become magnetic when they are in a magnetic field
what do compasses show?
that in most places the earths magnetic field is not parallel to the ground
wires with electric current have a...
magnetic field
what does the strength of the magnetic field at a point around a wire with current depend on?
the size of the current and also on the distance from the wire
what is an example of a strong electromagnet or solenoid?
a coil of wire with an iron core
flemings land hand rule- what does each finger stand for?
thumb - force, index finger - field, middle finger - current
how do motors work?
forces on a coil carrying an electric current in a magnetic field produce a turning effect