RLC Circuit

Discussion in 'Homework Help' started by Lexi, Jan 4, 2009.

  1. Lexi

    Thread Starter New Member

    Jan 4, 2009
    6
    0
    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?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
  3. jw223

    New Member

    Jan 3, 2009
    9
    0
    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
     
  4. jw223

    New Member

    Jan 3, 2009
    9
    0

    when XL > Xc then z = sqrt((R*R) + [(XL-Xc)*(XL-Xc)])
    z = sqrt((25*25) + [(60-45)*(60-45)])
    z = 29.155ohms
     
  5. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    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
     
  6. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    This is always true, not only when XL>Xc.
     
Loading...