May 7

Impedance

In today's lab, we measure impedances of resistors, capacitors, and inductors. The measured values will be compared with the expectations values.

Zc = 1/(jwc)

Zl = jwlL

Zr = R

Zseries = Z1 + Z2 + Z3 .....

Zparallel = 1/ ( 1/Z1 + 1/Z2  + 1/Z3 + .......)

We setup three circuits each with a 47 ohm resistor in series with a resistor, an inductor, or a capacitor.

 From left to right: RC, RL, RR circuit.

There is no phase shift for the RR circuit.

 For the inductor the current lead the input voltage by around 90 degree. The frequency have affect on the angle.

For the capacitor, the input voltage lead the voltage across the capacitor by around 90 degree. The frequency have affect on the angle.