Question

As the frequency of an ac circuit increases, the current first increases and then decreases. What combination of circuit elements is most likely to comprise the circuit? [NCERT Exemplar]
(a) Inductor and capacitor.
(b) Resistor and inductor.
(c) Resistor and capacitor.
(d) Inductor only.

Answer 1

Answer:

As the frequency of an ac circuit increases, the current first increases and then decreases. What combination of circuit elements is most likely to comprise the circuit Inductor and capacitor. resistor

in a circuit Imax will be maximum when reactance is minimum. on icreasing frequency in LCR circuit the reactance.XL = 2πvL due to inductance will increases and due to capacitance it will decreases.

Z = impedance of the circuit.

   $\sqrt{R XR+XL-XC} ^{2}$

AS frequency increases, z decreses and at a certain value of frquency known resonant frequency Vc impedance Z is minimum.

current varries inverslay with impedance.

so option 1 and 2 are correct.