We haven't started on Electrochemistry at school yet, but I did manage to find some time to read up on the topic. One thing I've noticed from when I started, is that different books and sites use different terms for the same symbols (For example: One book says Molar *conductivity* is represented by $\Lambda$, but another says it's Molar *Conductance*, and another book makes use of *both* Molar Conductance and Molar Conductivity, albeit inconsistently).

Now, my school textbook, as well as another book, *Physical Chemistry* by Wallwork and Grant employ the following equation for ionic conductivity:

$$\lambda=F\mu$$

Where $F$ is the Faraday constant and $\mu$ is the ionic mobility of the ion under consideration.

But I saw [another equation on Wikipedia][1] 

> $$\lambda=zF\mu$$

> Where $z$ is the ionic charge of the ion being considered.


So my question is, which of these equations are right? 
  [1]: https://en.wikipedia.org/wiki/Molar_conductivity