Explanation
At resonance net voltage across L and C is zero.
In purely inductive circuit voltage leads the current by 900.
In R-C circuit current increases exponentially with time, so correct graph will be (a).
For anti-resonant circuit current is minimum at resonant frequency and at frequencies other than resonant frequency current rises with frequency.
We can use a capacitor of suitable capacitance as a choke coil because average power consumed per cycle in an ideal capacitor is zero. Therefore, like a choke coil, a condenser can reduce ac without power dissipation.
Like direct current, an alternating current also produces magnetic field. But the magnitude and direction of the field goes on changing continuously with time.
Both ac and dc produce heat, which is proportional to square of the current. The reversal of direction of current in ac is immaterial so far as production of heat is concerned.
Since voltage is lagging behind the current, so there must be no inductor in the box.
Please disable the adBlock and continue. Thank you.