Matrix - Electronic Circuits and Components | AlternatingCurrent / Worksheet: Capacitive Reactance

Objective:	To investigate the action of a capacitor when connected to an a.c. supply.
Underpinning knowledge:	Alternating current and voltage. Capacitance. Reactance. Ohm's Law.
Apparatus:	TINA circuit file, or apparatus to make the following circuit.
TINA Circuit File:	Click here to download circuit file
Initial Settings:	C = 1湩, a.c. Supply of 10V at 100Hz
Requires:	Paper, Linear graph paper, pen or pencil.
Instructions: (a) Using initial settings determine X_C from X_C = V/I. (b) Calculate X_C from X_C = 1/(2π f C). (c) Compare the results from (a) and (b) (they should be the same!) (d) Vary the frequency of the a.c. Supply from 100Hz to 10kHz (we suggest that you use the following values: 100Hz, 200Hz, 400Hz, 1kHz, 2kHz, 4kHz, and 10kHz) and, at each frequency, measure and record the current flowing in a table. (e) Determine the reactance, X_C, at each frequency in (d). (f) Plot a graph of reactance, X_C, against frequency, f, using the data from (e).
Observations: Confirm that, X_C = V/I = 1/(2π f C). Comment on the shape of the graph. Does capacitive reactance increase or decrease with frequency?
Further work: Determine the value of capacitance that would exhibit a reactance of 100Ω at 1kHz.