RLC Circuit

Lexi

Joined Jan 4, 2009
6
If a series RLC circuit contains a 25 ohm resistance, a 45 ohm capacitive reactance and a 60 ohm inductive reactance, what is the total impedance?

beenthere

Joined Apr 20, 2004
15,808

jw223

Joined Jan 3, 2009
9
Hi Lexi

When XL > Xc Z = SQRT((R*R) + [(XL - Xc)*(XL*Xc)])

your value; R = 25ohms, XL = 60ohms, Xc = 45ohms

z = SQRT((25*25) + [(60-45)*(60-45)])

Z = 29.155ohms

jw223

Joined Jan 3, 2009
9
If a series RLC circuit contains a 25 ohm resistance, a 45 ohm capacitive reactance and a 60 ohm inductive reactance, what is the total impedance?

when XL > Xc then z = sqrt((R*R) + [(XL-Xc)*(XL-Xc)])
z = sqrt((25*25) + [(60-45)*(60-45)])
z = 29.155ohms

mik3

Joined Feb 4, 2008
4,846
If a series RLC circuit contains a 25 ohm resistance, a 45 ohm capacitive reactance and a 60 ohm inductive reactance, what is the total impedance?
Impedance of the capacitor is -j45 ohm, of the inductor is +j60 ohm and of the resistor is 25 ohm.

Thus,

total impedance Z=25+j60-j45=25+j15

in polar form

|Z|=sqrt[(25^2)+(15^2)]=29.15

arg Z=arctan (15/25)=30.9 degrees

thus Z=(29.15<30.9) ohm

mik3

Joined Feb 4, 2008
4,846
when XL > Xc then z = sqrt((R*R) + [(XL-Xc)*(XL-Xc)])
z = sqrt((25*25) + [(60-45)*(60-45)])
z = 29.155ohms
This is always true, not only when XL>Xc.