Sol. It can be seen that during the time interval from 0 to t 0 , the voltage across the capacitor is zero, the charge on it is also zero, there is no current through it and hence V CD is zero during this time interval (fig.). During the time interval from t 0 to 2t 0 , the voltage across the capacitor and hence the charge on its plates, grows linearly and hence a direct current passes through the circuit. This means that the voltage V CD is constant. During the time interval from 2t 0 to 3t 0 , the voltage across the capacitor does not change. Hence current does not flow, and V CD is zero. Finally, during the time interval from 3t 0 to 5t 0 , the capacitor is discharged, the current through the resistor is negative and constant and its magnitude is half the value of the current during the time interval from t 0 to 2t 0 .