If you had a circuit consisting of a voltage source in parallel with a resistor which is in parallel with an inductor, the relationship between the voltage input and the total current looks like this.

Why does it look like this?
Also with true power up the y-axis instead of current the graph is almost identical in shape. Why is this?

I've looked into the maths and I can't explain why the graphs look like this, I'm sure its quite simple but I can't seem to get my head around it.

cheers

 

Post the circuit.

 

Its just a voltage source connected to a resistor and inductor in parallel.

 

A DC voltage source?

 

Its a AC source.

 

\(Z_{eff.} = R || sL = \frac{sLR}{R + sL} = \frac{sLR}{R + sL} \cdot \frac{1/sL}{1/sL}
= \frac{R}{1+ \frac{R}{sL}} \\
i_{source} = v_{source}/Z_{eff.}
= v_{source} \cdot \frac{1 + \frac{R}{sL}}{R}
= \frac{v_{source}}{R} (1 + \frac{R}{sL})
\)

Is this what you get? This follows Ohm's law, not the given graph.

 

What is the frequency, the inductance and the resistance?

How did you get that graph?