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.