Current and Voltage Phasor diagram for an analog component

[Hanumantas]

Hello All,

I have one basic question..

We all know that current leads the voltage by 90 degree for Capacitor and vice-versa for inductor.
Does it means (for capcaitor), that current will reach maximum before voltage reaches maximum value.

Someone please tell me the physical meaning of this..
Also does this concept plays significant role for analysing and designing the analog circuit like RC filter etc.

Thanks

 

[gasingh]

The concept of 90deg phase is valid only when you are talking about a sinusoidal input system and that too once it has reached the steady state , SO the only truth here is that In a system where the voltage across a capacitor is given by Vsinwt , the current in it will be Vsinwt/Xc = Vsinwt.*jwC = (wC)jVsinwt , In phasor notation multiplication by j is clockwise rotation by 90deg , so I = wC.Vsin(wt + 90) , which you say as current leads the voltage by 90deg , Apart from these special conditions , always use the differential equation to find current in the capacitor.