A low-pass filter consists of a 114μF capacitor in series with a 155Ω resistor. The circuit is driven by an AC?

1 Answer

• A) fc = 1/(2*pi*R*C) = 9 Hertz

  C) when f= fc, Vc = 0.707(V in)

  This is because Xc = R

  Vc = (V in)(jXc/(R + jXc) = (V in)(j/(1+j)

  |Vc| = |V in|(1/(sqrt 2) = 0.707 Vin

  B) when f = 1/2(fc), Vc = 0.89(V in)

  Xc = 2R

  Vc = (V in)(j2/(1 +j2)

  |Vc| = |V in|(2/(sqrt 5) = 0.89(V in)