# Electronics - RL Circuits - Discussion

### Discussion :: RL Circuits - General Questions (Q.No.1)

1.

As frequency increases

 [A]. both series and parallel RL impedance decrease [B]. series RL impedance decreases and parallel RL impedance increases [C]. series RL impedance increases and parallel RL impedance decreases [D]. both series and parallel RL impedance increase

Explanation:

No answer description available for this question.

 Dinesh said: (Sep 22, 2011) Xl=2pifl. In both the cases inductive reactance will increase with respect to frequency. Hence increase in impedence.

 Situ Dash said: (Nov 9, 2011) In both series & parallel Xl=2*pi*f*L So as freq increases Xl value increases & hence impedance increases.

 Sri Harshith Rajam said: (Dec 22, 2011) Inductive Impedance (X)= Omega*Inductance As omega is directly proportional to the frequency (2*pi*f) , the impedance increases and the inductor circuit tends to enter into the open circuit state !

 Bhanu said: (Apr 22, 2012) In parallel the real impedence is in dinominator so optiion c is coorrect.

 Jaydeep Gidhvani said: (Jan 10, 2013) Z=impedance Z=R+XL XL=2*Pi*F*L. F Increase XL Increase SO Impedance increase.

 Raheel Ahmed said: (Mar 2, 2013) When the frequency of Parallel RL Circuit Increases, XL increases which causes IL (current through inductor) decreases. Decrease in IL causes It (It=Il+Ir) to decrease, which means by relation IT=Vs/Zt, the Zt (Total Impedance) Increases.

 Jyothis said: (Sep 12, 2015) Find effective impedance of both series and parallel circuits. Analyse what happens when omega increases.

 Samurtza said: (Aug 31, 2017) Z(w)_Series=R+jwL. Z(0)_Series= R & |Z(infinite)_Series|= infinite (w increases , |Z| increases in SERIES) [Open at High frequency]. Z(w)_Parallel=1/(1/R-j/wL) . |Z(0)_Parallel |=infinite & Z(infinite )_Parallel = R ( w increases , |Z| decreases in PARALLEL) [Short at DC].

 Samurtza said: (Aug 31, 2017) Can be seen via MATLAB (Option C is correct) w=0:1/10:2*π; % RL Impedance Increases. R=1; L=1; Zs=R+j*w*L; Zp=1./(1./R+1./j*w*L); % normalized plots. plot(w,abs(Zs)/max(abs(Zs)),w,abs(Zp)/max(abs(Zp))).