Says here: https://ackspace.nl/w/images/b/b1/Cat5_reference_sheet.pdf that the inductance per meter of a Cat 5 cable is 525 nH/m. I have a 1.5m Cat5 Ethernet cable. Say if I don't have any means of measuring the inductance directly, so I'll just go by the calculation of 1.5m * 525 nH/m = 787.5nH.

So do I expect a self inductance approximately of 787.5nH on each wire pin to pin?

 

So do I expect a self inductance approximately of 787.5nH on each wire pin to pin?

No.
It will depend upon whether the two wires are part of the twisted pair or not.

Why are you concerned about self inductance of the wire?

 

Why would it be the the inductance of a pair? The other characteristics are given for a single conductor.

 

Why would it be the the inductance of a pair? The other characteristics are given for a single conductor.

You said pin to pin, so I thought you were measuring a pair of wires but I see know you meant end-to-end of one wire.
So yes, you just multiply inductance per unit length times the length.

 

The inductance of a single wire without the circuit being closed is of little practical use for most of us other than calculating the impedance. So we may understand your question precisely, please tell us what you would like to do with the inductance?

 

I've been told that the inductance per distance of 525 nH/m is when you close the loop of a pair, not of one wire. Thankfully, crutschow was honest enough to correct this. Kinda surprising that this forum would have more professional contributors than the other site I usually visit.

 

If you make the wire into a loop then the measured inductance will also be a function of the diameter and shape of the loop.

 

I've been told that the inductance per distance of 525 nH/m is when you close the loop of a pair, not of one wire. Thankfully, crutschow was honest enough to correct this. Kinda surprising that this forum would have more professional contributors than the other site I usually visit.

(Emphasis added after quoting)

Nicely put. Please tell your friends!

 

One other thing to keep in mind is that the inductance is not a big issue if the cable is properly terminated. The information you posted says the impedance is 100 ohms. I suspect that this is for a wire pair operated differentially so the 100 ohms would go across the input of the differrential receiver.

 

Yep, completely agree with the previous message about properly terminated ethernet cables.
I have recently found very detailed information about this issue. If someone still interested, I could share with you.