Q.

For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is 2.5 nF. If resistance of 200 Ω and 100 mH inductor are being used in the given circuit.

The frequency of ac source is _________ ×103 Hz. (given π2=10)              [2024]


Ans.

(10)      For maximum current, circuit must be in resonance.

            At resonance, XC=XL

           ωL=1ωCω2=1100×10-3×2.5×10-9=4×109

          (2πf)2=4×109

          f2=108f=104Hzf=10×103Hz