Electrical Engineering - Capacitors - Discussion

Discussion :: Capacitors - General Questions (Q.No.2)

2. 

A capacitor and a resistor are connected in series to a sine wave generator. The frequency is set so that the capacitive reactance is equal to the resistance and, thus, an equal amount of voltage appears across each component. If the frequency is increased

[A]. VR > VC
[B]. VC > VR
[C]. VR = VC
[D]. VR and VC = 0

Answer: Option A

Explanation:

No answer description available for this question.

Remya said: (Dec 15, 2010)  
xc=1/2pifc

Siva Naik said: (Dec 16, 2010)  
if xc is increases then inversely frequency decreases.so that voltage across the capacitor is higher than that of voltage across the resistor

Suresh said: (Jul 5, 2011)  
Xc=1/(2pi.f.c) It shows that the reactance of capacitor is dependent about frequency.

If frequency increased then the reactance will be decreased.

But the resistanse is independent about frequency.

I hope you will understand.

Xyz Mishra said: (Aug 19, 2011)  
Vr>Vc. Because with increase in frequency the valie of xc decreases. As xc decreases so the potential drop also decreses. On the other paryt the vr remains the same as resistior is independent of frequency. So vc<vr.

Priya said: (Sep 2, 2011)  
Xc = 1/2πfc
Xc ∝ 1/f
As f increases , Xc decreases --> Vc decreases
But R is independent of frequency --> Vr remains the same.
Hence Vr > Vc

Vaibhav said: (Oct 2, 2011)  
We know Xc=1/2pifcf, and if frequency increases then reactance decreases
and thus resistive voltage is greater than capacitive voltage or the frequency does not depend upon resistance hance resistive voltage unaffected by increase frequency while capacitive voltage decreases as initial by increase in frequency.

Sanat said: (Dec 26, 2011)  
xc=1/2pi.f.c;

So if f increases then xc decreases. So voltage drop across the 'C' decreases.

Sachchida Nand Maurya said: (Apr 2, 2012)  
We know that Vc=i.Xc & Vr=i.R
Given that
Vc = Vr
So f is inversely proportional to Vc.

Vr>Vc

Kaushal said: (Mar 10, 2013)  
Vc=i.Xc & Vr=i.R.

Given that
As given in question Vc = Vr
So f is inversely proportional to Vc.

Vr>Vc.

Sam said: (Jul 16, 2013)  
As we know fc=1/2pifc. So if frequency increases than vc will decrease.

Amarendra Dash said: (Aug 28, 2013)  
From the ques Vr = Vc.

So IR = IXc.

Xc inver.proper to f,
As f increase Xc decrease resulting IXc decrease i.e Vc decrease.

Hence Vr > Vc. answer.

K.Jeevitha said: (Aug 29, 2013)  
vc = i.xc and vr = i.r.

vc = vr.

So vr >vc.

Mike said: (May 21, 2014)  
Plain English. Capacitors allow a change in voltage to pass through. If it's allowing a higher frequency to pass through then the voltage drop on the capacitor lowers.

Sayali Sawant said: (Dec 19, 2014)  
Capacitive reactance is inversely propotional to the frequency but resistance is independent from frequency. So resistance is more than capacitance. So answer is vr > vc.

Fazl Hamad said: (Apr 22, 2015)  
Dear fellows.

AS xc = 1/2 pi.f.c as f increases inversely xc decrease,

Also vc = i. xc as xc decreases so voltage across capacitor decreases.

Thus vr is greater than vc.

Selvaguru said: (Jul 29, 2017)  
Frequency and capacitive reactance value are inversely proportional to each other, when fc increased reduces the value of Xc hence VR >Vc.

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