Monday, December 6, 2021 # Impedance

Impedance is represented by the letter Z and is measured in terms of ohms. Impedance can be thought of as the "resistance" to the alternating current in a circuit.

Z = V/I
Z = √ R 2 + X 2 where X is reactance
Z = √ R 2 + (XL- XC)2L where XL is Inductive Reactance and and XC is Capacitive Reactance

Example 1:
If you have a circuit with 240V ac- circuit pulling 10A, what's the impedance of the said circuit.

Z = V/I
Z = 240V/10A
Z = 24 Ω

Example 2:
What's the impedance of a circuit (ac) with a reactance 12 Ω and a resistance of 8 Ω

Z = √ R 2 + X 2
Z = √ (8 Ω) 2 + (12 Ω) 2
Z = √64 Ω 2 + 144 Ω 2
Z = √ 208 Ω 2
Z = 14.42 Ω

Example 3:
What's the impedance of an AC circuit with or resistance of 10 Ω, an inductive resistance of 20 Ω and capacitive reactance of 14 Ω

Recall that XL is inductive resistance and Xc is capacitive reactance

Z = √ R 2 + (XL- XC) 2
Z = √ (10 Ω) 2 + (20 Ω - 14 Ω)2
Z = √ 100 Ω 2 + (6 Ω) 2
Z = √ 100 Ω 2 + 36 Ω 2
Z = √ 136 Ω 2
Z = 11.66 Ω