How Do I Combine Capacitor and Inductor Impedances in Parallel?

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To combine capacitor and inductor impedances in parallel, the correct approach involves using reactance instead of impedance. The formula for equivalent reactance is Xeq = 1/[(1/Xc) + (1/XL)], where Xc represents capacitive reactance (always negative) and XL represents inductive reactance (always positive). It's important to note that impedance (Z) includes both real and imaginary parts, while reactance (X) focuses solely on the imaginary component. The values for capacitive and inductive reactance should be treated as purely imaginary numbers. Understanding this distinction is crucial for accurately calculating the equivalent reactance in parallel circuits.
swooshfactory
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Homework Statement



How do I combine these into an equivalent impedence? I'm dealing with complex impedence, but I'm not sure how to make them into an equivalent impedence.

Homework Equations





The Attempt at a Solution



I guess Zeq= 1/[(1/Zc)+(1/ZL)].
Is this right?
 
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Or do I replace the capacitor by an open circuit and inductor by a short?
 
swooshfactory said:
I guess Zeq= 1/[(1/Zc)+(1/ZL)].
Is this right?

It looks pretty good to me, however I'd like to clarify a little terminology.

Z represents a complex value called impedance with both real and imaginary parts. Often however it is given as a single number which represents just the magnitude without the angle. As magnitude it is always positive.

Zc & ZL aren't correct because those values are always imaginary with no real part. Instead, the term X is used and it's called reactance.

Capacitive reactance (Xc) is always negative and Inductive reactance (XL) is always positive.

With no real parts the formula would be Xeq = 1/[(1/Xc) + (1/XL)].
 
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