# inductor opposition to AC

Discussion in 'General Electronics Chat' started by samjesse, Feb 21, 2010.

1. ### samjesse Thread Starter Active Member

Sep 14, 2008
202
0
Hi

Would a coil of one wire x 100 turns and another of 100 wires x one turn each, have the same opposition to AC? and why?

Many thanks

2. ### Wendy Moderator

Mar 24, 2008
20,735
2,499
Not necessarily. There are many things involved, simple number of turns does not mean they will be the same inductance. Diameter, for example, makes a difference, as well as length. There are many calculators on the web that will tell you your inductance according to the physical parameters.

It is the value of inductance, that resists AC.

3. ### samjesse Thread Starter Active Member

Sep 14, 2008
202
0
Thanks Bill

I thought it is implied in my question that all other variables remain the same. but maybe not.

thx

4. ### Wendy Moderator

Mar 24, 2008
20,735
2,499
Sure, if the coils were mechanically similar, they would be very close to the same values electronically. Slight mechanical differences is what causes tolerance drift.

Coils are the simplest of components to build. They can be the hardest to understand and predict over a frequency band.

5. ### ifixit Well-Known Member

Nov 20, 2008
638
108
If a coil of 100 turns has 100 times the inductance of a seperate coil of 1 turn, then connecting 100 of the 1 turn inductors in series will give you the same inductance as 1 inductor of 100 turns.

The formula for adding inductance of more than one inductor together is:

Lt = L$^{1}$ + L$^{2}$ + L$^{3}$ ... L$^{100}$

If the 1 turn inductors are wound on the same core and all connected in series then the resulting total inductance will not be 100 times the inductance of one turn alone.