## Calculations on an inductor and resistor in series.

An inductor causes a 90 degrees phase shift. After reading the previous section, it's clear that the
complex impedance can be written as:

So: |Z_{R+L}| =
√(R^{2}+X_{L}^{2})
and arg(Z_{R+L}) =
arctan(X_{L}/R).

As an example, we'll take a 10k resistor in series with a 15.9k
inductor. The total (complex) impedance is 10k + 15.9kj. The absolute
value is √(10k^{2} +
15.9k^{2}) = 18.78k. The phase shift in the
current flow will be arctan(15.9k/10k) = 57.8 degrees.