Inductance / Inductive Reactance

Which physical properties of coils increase inductance?

turns

permeability

core area

shortness of path

Define induction

voltage produced by interaction of magnetic field and conductor

What happens during self induction when current changes?

the induced voltage opposes the applied voltage when current increases…

and aids the applied voltage when current decreases

induced voltage is proportional to the rate of change of current

What happens when DC voltage is applied to an inductive circuit?

current does not rise instantly, but at rate determined by inductance

What is a time constant (T) (inductors)?

the ratio of inductance (L) divided by resistance (R)
T = L / R

T is in seconds

time required for current to reach a steady value = 5 x T

What can happening when opening an inductive circuit?

Collapsing magnetic field can induce a high voltage into the circuit “inductive kick”

Induced EMF = ( Change in current / Change in time ) x L

can be prevented by using a discharge resistor