# Electronics - RL Circuits - Discussion

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

1.

As frequency increases

Discussion:

9 comments Page 1 of 1.
SAMurtza said:
6 years ago

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))).

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))).

SAMurtza said:
6 years ago

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].

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].

Jyothis said:
8 years ago

Find effective impedance of both series and parallel circuits. Analyse what happens when omega increases.

Raheel ahmed said:
1 decade ago

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.

JAydeep Gidhvani said:
1 decade ago

Z=impedance

Z=R+XL

XL=2*Pi*F*L.

F Increase

XL Increase

SO Impedance increase.

Z=R+XL

XL=2*Pi*F*L.

F Increase

XL Increase

SO Impedance increase.

Bhanu said:
1 decade ago

In parallel the real impedence is in dinominator so optiion c is coorrect.

Sri Harshith Rajam said:
1 decade ago

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 !

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 !

Situ dash said:
1 decade ago

In both series & parallel

Xl=2*pi*f*L

So as freq increases Xl value increases & hence impedance increases.

Xl=2*pi*f*L

So as freq increases Xl value increases & hence impedance increases.

Dinesh said:
1 decade ago

Xl=2pifl. In both the cases inductive reactance will increase with respect to frequency.

Hence increase in impedence.

Hence increase in impedence.

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