Electromagnetic Induction Flashcards
Explain electromagnetic induction
The electrons of a conductor in a mag field experience a force causing them to accumulate at one end.
This induces an emf which induces a current
How is an emf induced in a magnetic field?
When there are changes in mag flux
lines of flux are cut
What does flux cutting result in?
Always induces emf
Induces current if complete circuit
What is flux linkage?
flux times no of turns in coil
What is faradays law
Induced emf is directly proportional to the rate of change of flux linkage
What is lenz’s law
Induced emf is always in a direction to oppose the change that caused
Why does induced emf oppose the change?
To conserve energy
How to investigate induced emf?
Dropping a magnet through a coil
What is NxFi and units?
Flux linkage , Wb
What is d(NxFi)/dt
=emf induced
Rate of change of flux linkage
An emf is only induced in a conductor when?
The magnetic flux linked with the coil changes
state lenzs law in terms of flix
Induced current flows to produce its own magnetic field and flux which acts im a direction to opposethe change in mag flux that occured to restore it to its original value
State lenzs law in terms of forces
Induced current flow to produce its own mag field, this interacts with external mag field to produce a force that opposes the original motion that induced the current
