Determining resistors in AC/DC circuit

[johnsholto]

I have trouble with determining the type of resistor used in the following problem.

A type of black box is connected to an AC/DC circuit. The values of U and I are given in the DC circuit, the value of R is not. The values of U and R are given in the AC circuit, the value of I is not.

In the DC circuit the values of U and I are.
U=0 I=0
U=1 I=360
U=2 I=500
U=3 I=650
U=4 I=750
U=5 I=850

Now, R is calculated using U=R*I, right?

So the values of R would be:
R0=-
R1=1/360
R2=1/250
R3=3/650
R4=2/375
R5=1/170

In the AC circuit the values of U and R are:
U=0 R=0
U=1 R=2.7
U=2 R=3.3
U=3 R=4.5
U=4 R=5.3
U=5 R=5.8

The values for I would be according to U=R*I:
I0=-
I1=0.37
I2=0.6
I3=0.66
I4=0.75
I5=0.86

Now, how do I determine the type of resistor that has been used in these circuits? I assume that it is not a capacitor as there is current flow in the DC circuit.
Furthermore, the values of I in the AC circuit is approximately the value of I in the DC circuit*1/1000.

 

[jbsteele]

Based on the values of U and R in the AC circuit, it can be seen that the resistor used is a variable resistor. Variable resistors are typically used to control the current flow in a circuit and adjust its resistance as needed.