- At High Frequency:
Inductive Reactance XL is greater than capacitive reactance XC due to which circuit behaves as R-L Series Circuit in which voltage V leads to the current I by 90° or π/2 (As, f ∝ XL and f ∝ 1/XC. So, when f increases XL > XC ).
- At Low Frequency:
Capacitive Reactance XC is greater than inductive reactance XL due to which circuit behaves as R-C Series Circuit in which voltage V lags to the current I by 90° or π/2 (As, f ∝ XL and f ∝ 1/XC . So, when f decreases XL< XC ).
- At Intermediate Frequency
In between these frequencies, there will be a certain value of frequency at which XL becomes equal to XC and this frequency is called resonance Frequency.
- At resonance, XL = XC, so they are equal and opposite to each other and cancel each other’s effect and circuit behaves as resistive circuit.
- By changing frequency if XL= XC,This circuit becomes the resonant circuit.
- Impedance of circuit becomes minimum and is equal to R (resistive circuit).
- Power loss at resonance is maximum.
- The variation of current with frequency is giver by the graph given below:
- VC > VL (At high frequency)
- VC= VL (At resonance frequency)
- VC < VL (At low frequency)
- At Vc>VL: