Which would need the strongest electromagnet? a) a bell b) an MRI scanner c) a loudspeaker
b) an MRI scanner
Do conductors or insulators have a higher resistance?
insulators
an object or type of material that allows the flow of charge (electrical current) in one or more directions.
conductor
a material in which the electron does not flow freely or the atom of the material
insulator
What shows how difficult it is for current to flow through a circuit
resistance
Electricity that has several paths the current can take
parallel circuit
Name at least one advantage of an electromagnet over a regular magnet
Any of these (other possible answers) adjustable strength, greater control over the magnetic field and durability
A voltmeter measures
potential difference
The part of a circuit which can control whether electricity flows
switch
A container consisting of one or more cells, in which chemical energy is converted into electricity and used as a source of power.
battery
Which of the following would be the better insulator? Plastic, copper wire, graphite
plastic
In a magnet: north poles __________ north poles
repel
How can you change the direction of an electromagnet run on batteries?
turn the batteries around
What happens to an electromagnet if there are fewer turns on its coil?
it gets weaker
A force on a magnet or magnetic material is called....
magnetic field
a soft metal core made into a magnet by the passage of electric current through a coil surrounding it.
electromagnet
What type of core makes an electromagnet stronger?
iron
When electricity flows it is called a __________________
current
What does this image show?
magnetic field lines
Charge of electrons
negative
When a switch is opened in a circuit it is referred to as
incomplete (circuit)
Potential difference divided by resistance equals
current
Electromagnets usually have a magnetic material in the centre of the coil called a __________.
core
In a magnet: north poles __________ south poles
attract
Current in a circuit flows in which of the following directions listed below:a) In direction from high potential to low potential (b) In direction from low to high potential c) In direction of flow of electrons d) In any direction
In direction from high potential to low potential.
visual tool used to represent magnetic fields
magnetic field lines
A compass contains a small ___________ which can spin
magnet
What happens to an electromagnet if you use more batteries?
it gets stronger