**Competency Group**: Electrical Engineering

**Type**: Design, Modeling and prototyping Hardware

**Description**: Capacitive and inductive loads oppose the
flow of alternating currents. This opposition is expressed as
impedance at a given frequency. The effect of a real-world
impedance load is observed as an attenuation of the signal and a
phase shift. Because of the nature of the impedance, it is denoted
as a vector whose angle is the same as the phase angle between
voltage and current, and the magnitude of the impedance is the same
as the quotient between the voltage and current magnitudes. E.g.
Probes are used to measure the relative inductance/capacitance of a
circuit.

**Citation for Description**: National Instruments. (2011).
Capacitance/ Inductance Measurements. Retrieved from http://www.ni.com/white-paper/3078/en

**Units**: Henries, Farads

**Advantages**: The frequency of operation of a device (say
mains frequency) will have a frequency dependent load, which must
be measured in terms of magnitude and phase.

**Limitations**: Can involve the use of an oscilloscope which
can be quite expensive.

**Regulations**: IEEE Standards Organization. (2012).
Retrieved from http://standards.ieee.org/

**Target Audience**: Engineering

**Relevant to Universal Design**: No

**Stages and Steps**: 2.2, 5, 6

**Free Resource**: Calculatoredge. (n.d). L-C Resonance
Calculator. Retrieved from http://www.calculatoredge.com/new/resonance.htm

**Purchase Resource**: Rawlins, J.C., & Fulton, S.R.
(2000). *Basic AC Circuits.* Woburn, MA:
Butterworth-Heinemann.