Inductor and resistor in an ac circuit.

  What happens if we replace the capacitor in the previousw section with an inductor? With the capacitor, depending on the direction of the current and the polarity of the charge on the capacitor, currents can charge or discharge the capacitor, thereby increasing or decreasing the voltage V_C across the capacitor. An inductor on the other hand, always opposes changes in the current flowing through it. Unlike the voltage V_R across the resistor, which is simply proportional to the current, the the voltage V_L is proportional to the change in the current, which is maximum near zero crrent and minimum at current extrema. As aq result, V_L and V_R are 90 degrees out of phase, with the V_L leading V_R (or the current). As can be seen in the applet below, it is clear that the applied voltage V_app is simply the vector sum of V_R and V_L. Click on the "Show Current" button in the applet below to see the current flowing in this circuit.

  Since the impedance of a inductor depends on the driving frequency, V_L will change, which in turn will change the amount that V_L leads the applied voltage, when the driving frequency changes. Try changing the frequency in the applet below.

Use the above simulation to answer the following questions?