# Inductance and Capacitance per Temperature

1. Nov 23, 2008

### americanforest

I am studying the relationship between transmission speed in a Transmission Cable and the temperature of the cable. This speed is given by (as per discussion in the Feynman lectures)

$$v=\frac{1}{\sqrt{LC}}$$ where
• $$L$$ is the inductance per unit length
• $$C$$ is the capacitance per unit length

Does anyone know how the inductance and capacitance are expected to vary with temperature? The range examined in the experiment is approximately 20-50 degrees Celsius.

2. Nov 23, 2008

### f95toli

How much it will change basically depends on the properties of the dielectric (I am assuming you are refering to a coaxial cable).
The change should be very small assuming one of the more common dielectric is used, e.g. PTFE etc. I doubt creep will be much of an issue in such a small temperature range.

Also, if the range in question includes room temperature you should be able to find this data in a datasheet, they typically list data from -50 to +80 degrees C or so, at least if the cable conforms to military specs (and most coaxes do)

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