Magnetic Fields, Forces and Motors Flashcards
What are properties of magnetic materials?
- They are dipolar
- They attract ferromagnetic material
- They can magnetize ferromagnetic materials as it aligns the dipoles of the domains
- They interact with other magnets
- They will align with earth’s field
- It produces a magnetic field around it
What is interesting about earth magnetic poles?
The south pole has a north magnetisation and the north pole has a south magnetisation.
What is a solenoid?
It amplifies the magnetic field by causing the field lines of the straight wires to line up and gain magnitude
What happens to charged objects in magnetic fields?
They will experience a force perpendicular to velocity and the magnetic field
How does a velocity selector work?
There is an overlay of a magnetic and electrical field, where only particles of qvB=Eq are able to pass through.
Too fast = up
Too slow = down
How does a mass spectrometer work?
- Particles enter the selector so that v=E/B
- The charged particles enters the mass spectrometers magnetic field, causing the particle to travel in circular curves
- Detectors measure the radiuses
- At this point, only mass affects the radius as the speed is the same. (F=QvB=mv^2/r) —— (r=mv/QB)
What is the power supply in a motor?
DC power is supplied to the coils
What is the coil in a motor?
Copper wire that allows a current to run through it
What is the armature in a motor?
Is the whole rotating armature.
It usually consists of coils where the more coils increases the forces (The current through the magnetic field is put through more times).
What is the purpose of a magnet in a motor?
The magnet is curved to bend the magnetic feilds
What is the stator in a motor?
The stationary part
What is the rotor in a motor?
The rotational part
What is the split-ring commutator in a motor?
It is used to reverse the direction of the current to continue the motion of the motor
What are the brushes in a motor?
They transfer the power to the split-ring commutator
