electromagnetism Flashcards
How would you describe a uniform magnetic field?
*The field lines are equally spaced and parallel to each other.
*The magnetic flux desnity is the same at any point in a uniform field.
Describe the use of field lines for magnetic fields
- more dense field lines show a stronger magnetic field
*the arrows represent the direction of a north pole if it was placed in the field
*arrows point from North to South
What is the Right Hand Grip rule?
*thumb points in the direction of conventional current
*the direction in whihc the fingers curl shows whether the magnetic field is clockwise or anticlockwise
What is the units for magnetic flux density?
Tesla
How do we use Flemmings Left Hand Rule?
*FBI
*F- thumb the direction of the force
*B- index finger the direction of the magnetic field
*I- Middle finger the direction of conventional current
Why do charged particles move in a circular path when travelling through a magnetic field?
as they travel through the field they experience the magnetic force which is perpendicular to it’s velocity. This is a centripetal force so the particle moves in a uniform circular path.
What is Magnetic Flux?
The product of the magnetic flux density perpendicular to an area and the crossecitonal area it travells through.
What is the units for magnetic flux?
Webers (Wb)
When is Magnetic flux at a maximum?
When the magnetic field is perpendicular to the area
When is the Magnetic flux equal to zero?
When the magnetic field is parallel to the area.
What is Magnetic flux linkage?
The product of the number of coils and the magnetic flux
What is Faraday’s Law?
The rate of change of magnetic flux is directly proportional to the emf induced.
What is Lenz’s law?
The direction of the induced current opposes the change (in magnetic flux linkage) producing it.
