3.11 Inductance Flashcards
An electromotive force is developed when
There is relative motion between a magnetic field and a conductor.
How can Induced EMF be increased?
Increasing magnetic field, increasing the rate of change of flux, increasing the amount of conductore turns/coils increasing the area of the conductor thats getting cut.
How can you vary the movement of a magnetic field
By increasing or decreasing the current through the conductor, which will expand or collapse the magnetic field.
What will create self inductance of a conductor?
The reversal of current through the conductor., reffered to as a Self infuced EMF
Define mutual inductance:
When a conductors magnetic flux induces a voltage in another electrically isolated/seperate conductor/circuit it is called mutual inductance, it is said to be magnetically coupled.
Mutual inductance depends on:
Number of turns in each coil, physical size of each coil, permeability of each coil, position of coils to each other.
What is one method of increasing mutual inductance greatly?
By mounting the coils on a common iron core.
Define Coefficient of coupling
coupling between 2 coils equals the ratio of the flux cutting one coil to the flux originated in the other coil.
If all of the flux produced by one coil cuts only half the turns of the other coil what is the coeffcient of coupling?
K = .5
What is the formula for Mutual inductance?
M=K to the square root of L1 x L2
After saturation, no increase in the amount of current through the primary circuit….
will increase the amount of mutual induction that is induced in the secondary circuit.
IMPORTANT inductance definition:
Induction is the characteristic of an electrical conductor that opposes change in current.
Why are inductors referred to as chokes, reactors or coils.
inductors chokes off and restricts sudden changes in current, they react in changes of either increasing or decreasing current.
What are cores of an inductor made from?
Either AIR or SOFT IRON
What factors affect coil inductance?
Turns in a coil, diameter of a coil, coil length, layers of windings in a coil, material used in the core.
