Inductors with apparent negative inductive reactance?

[Foilist]

1. I am currently progressing through my assignment, however I have been given a circuit with 2 values of Z:

Z1 has a magnitude of 30 and angle of -31.
Z2 has a real value of -12 and an imaginary number of -36.


2. When these are both converted to complex number format:

Z1 = 25.715 - j15.45
Z2 = -12 - j36

3. I have checked the question and at no point does it mention components, however from my research and reading, I have found that an impedance with a negative reactance (i.e. imaginary part) indicates a capacitor. My question is: is this a valid assumption to make?

I know it seems like a daft question, but I wouldn't want to make an assumption that then has a negative impact on my result!

Many thanks for any help offered!

 

[mda]

I would imagine that the presence of the negative real part is of more concern (wikipedia has a fairly comprehensive entry on this... well worth a read).

Generally the negative imaginary part is capacitance which can usually be considered separately due to superposition. However, given the special nature of negative resistance you should consider this more carefully.

 

[Foilist]

Many thanks for the help - didn't even register about the negative resistance!