A resistor for which \(R=60.0 \Omega\) is connected to an \(\mathrm{AC}\) source. The source emf is given by \(\mathscr{E}=\mathscr{E}_{\max } \sin \left(\omega t+\phi_{i}\right)\), where \(\mathscr{E}_{\max }=5.00 \mathrm{~V}, \omega=2 \pi(30 \mathrm{~Hz})\), and \(\phi_{\mathrm{i}}=\pi / 4\). At what instants is there no current in the circuit? If you replace the resistor with a capacitor for which \(\mathrm{C}=200 \mathrm{mF}\), at what instants is there no current in the circuit?