1. Fields and Waves
Lesson 4.5
INDUCTANCE
Darryl Michael/GE CRD

2. Inductances self inductance - e.g. inductors Two types of Inductances:
mutual inductance - e.g. transformers
Self Inductance:
coil of wire with
, creates
wire loop intersects
this creates

3. Self Inductance For 1 turn: For N turns: , and is independent of I
Do Problem 1
For 1 turn:
For N turns:
, and
is independent of I
Since
L depends on materials (through m) and geometry (like C)

4. Self Inductance In general: x N, because , because x N, because
Note: To calculate L, don’t need Faraday’s Law just need:
The flux linkage,
, only if all loops intersect same flux
not true for finite solenoid and will need:
Computation of
Can use either method
Do problem 2

5. Mutual Inductance Coil 1 Coil 2
Current through Coil 1 induces e.m.f. in Coil 2
Mutual Inductance:

6. Mutual Inductance
Mutual Inductance
where,
Also,
And,
Do Problem 3b