Magnetic Fields Page 140-141 Flashcards
What’s a magnetic field
A region where a force is exerted on magnetic materials
Magnetic fields can be represented by
Field lines
Also called flux lines
Field lines go from the… To the… Of a magnet
North
South Pole
The closer together magnetic field lines ( flux lines )are the… The field
Stronger
There is a magnetic field around a wire carrying…
Electric current
When current flows in a wire or any other long straight conductor what happens
The field lines are… Centred on the wire
The direction of a magnetic field around a current carrying wire can be worked out with…
If you loop the wire into a coil the field is doughnut- shaped ,while a coil with length(a…)Forms a field like a…
A magnetic field is induced around the wire
Concentric circles
Right hand rule
Solenoid
Bar magnet
A wire carrying a current in a magnetic field will experience…
A force
If u put a current-carrying wire into an external magnetic field (e.g …) , the field around the wire and the field from the magnets are…
This causes a …-lines closer together show ….
These bunched lines cause a…
The direction of the force is always… To both the current direction and the magnetic field – it’s given by Fleming’s left-hand rule
If the current is parallel to the field lines the size of the force is…– There is no component of the magnetic field perpendicular to the current
Between 2 magnets
Added together
Resultant field
Where the magnetic field is Stronger
‘Pushing’ force in the wire
Perpendicular
Zero N
Fleming’s left-hand rule
First finger points in the direction of the…
Second finger points in the direction of the…
Thumb points in the direction of the…
External uniform magnetic field
Conventional current
Direction of the force
The force on a wire is proportional to the…
Flux density
The force in a current carrying wire at a ..to an external magnetic field is proportional to the magnetic flux density B
Right angle
Magnetic flux density is sometimes called the
It’s defined as
Strength of the magnetic field
When current is at 90degrees to the magnetic field ,the size of the force is proportional to
The current , the length of the wire in the field ,as well as the slick density
F=BIL
Flux density is a
It’s measured in
Vector quantity with both direction and magnitude
Teslas
Think of flux density as the number of flux lines per
1 Tesla=Wb/m^2
Unit area
