<p>Does the current in an a.c. circuit lag, lead or remain in phase with the voltage of frequency applied to the circuit, when (i) f =&nbsp;<span class="equation">\(f_{r}\)</span>&nbsp;(ii) f &lt;&nbsp;<span class="equation">\(f_{r}\)</span>&nbsp; and (iii) f &gt; <span class="equation">\(f_{r}\)</span>,&nbsp;where&nbsp;<span class="equation">\(f_{r}\)</span>​​​​​​​ is the resonant frequency ?</p>