How do you calculate the impedance of the primary circuit?

[Andrei0408]

Homework Statement

I have an assignment that I need to do regarding magnetically coupled coils, but I'm stuck at a point. If we know the following: f=5000Hz, the distance between coils, x=20mm, the voltages U1=3.18V U2=336mV, the current I1=100.6mA, N1=250, N2=1000, how can I calculate the impedance of the primary circuit, Z1? I've looked it up online but I can't find any formulas with these particular given data. Any ideas?

Relevant Equations

M = U2/(ω*I1)

I'm not sure if it helps for what I'm looking, but I've calculated the mutual inductance, M, using the equation: M=U2/(ω*I1) = 106.3μH. I don't need the numerical value in particular, I just want to find a way to deduce the formula in order to calculate Z1. Thank you!

 

[tech99]

Do we know what the secondary is connected to?