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Strengthening Skills   Building Confidence

 

 

 

 

Procedure

figac1001.gif (1512 bytes)

This figure represents the simplest possible ac circuit--an ac voltage source connected to a single load.

The source voltage is expressed with zero phase

  • VT0 V for the rectangular form
  • VT +j0 V in rectangular form

The load may be

  • Purely resistive: Z10 W
  • Purely inductive: Z1+90 W
  • Purely capacitive: Z1-90 W
  • Inductive with a resistive component: Z1q
    where q does not equal 0, +90 or -90
  • Capacitive with a resistive component: Z1-q
    where q does not equal 0, +90 or -90

The total impedance of the circuit is equal to  Z1:

ZT = Z1

The total current is determined by Ohm's law:

equac1001.gif (963 bytes)

Examples

Example 1

Given: Z1 = 50 W, VT = 12 V
Find: ZT, IT

Solution:

ZT = Z1
ZT = 500 W

equac1002.gif (1031 bytes)
IT = 0.240 A

Note: This is a purely resistive circuit.

Example 2

Given: Z1 = 2490 W, VT = 12V
Find: Find: ZT, IT

Solution

ZT = Z1
ZT = 2490 W

equac1003.gif (1050 bytes)
IT = 0.5-90 A

Note: This is a purely inductive circuit.

Example 3

Given: Z1 = 10-50 W, VT = 12 V
Find: ZT, IT

Solution

ZT = Z1
ZT = 10-50 W

equac1004.gif (1060 bytes)
IT = 1.250A

Note: This is an RL circuit.

David L. Heiserman, Editor

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All Rights Reserved

Revised: June 06, 2015