
At a moment when the charge on capacitor is zero, the switch is closed. If be the current through the inductor at , for (initially, is uncharged.)



Important Questions on Alternating Current


If the instantaneous emf and the instantaneous current equations of an A.C. circuit are respectively.
then the phase difference between voltage and current is :






At a certain moment, the switch shown in the figure is disconnected. The energy of the oscillations immediately after the switch is disconnected and at time from the time switch is disconnected are, respectively


Obtain an expression for the energy associated with an inductor.






Using the equation
. for L-C-R circuit, obtain an equation for the complex current and explain its different terms in the equation. Hence obtain the equation for real current




If a student plots graphs of the square of maximum charge on the capacitor with time (t) for two different values and of L then which of the following represents this graph correctly? (plots are schematic and not drawn to scale)

