What is the Series Limit in a Spectral line What is exactly the series limit in a spectral line graph? Do we talk about series limits for each series (Eg: Lyman series in Hydrogen) or collectively for an atom?

Is series limit the transition having least energy or least wavelength?

So like for Lyman series, will series limit be that corresponding to $\ce{1 -&gt; 2}$ or $\ce{1 -&gt; Ionize}$?
Every series of wavelengths produced from the hydrogen atom excitations have a certain minimum limit. These minimum wavelengths are called the series-limit for that particular series. Take a look at this picture for example:



The minimum series of the Lyman series would be for the largest transition, which is from ∞$\ce{ -&gt; }$1. Plugging the values into the Rydberg's equation:

$$\frac{1}{\lambda}=R_{∞}\left(\frac{1}{1}-\frac{1}{∞}\right)$$

That should give us a value of 91nm. Which is the series-limit for the Lyman series. 

Now you can find series-limits for the other series as well.