The figure shows the vector diagram of reactances and resistances in an AC circuit. Construct a similar diagram for a circuit in which the current frequency is doubled and the emf amplitude is the same, and determine how the current will change as a result of this.

             

A circuit (Figure) contains an alternating emf, a resistance, and a reactive element (only a capacitance or only an inductance). What is this element if the time dependences of the current in the circuit and the emf of the source are those as shown in Figure ?

Are the readings of the a ammeter $A3$ equal to the sum of the readings of the ammeters $A1$ and $A2$ for the cases depicted in Figures ?

Are the readings of the voltmeter $V3$ equal to the sum of the readings of the voltmeters $V1$ and $V2$ for the cases depicted in Figures ?

The current flowing through the resistance in an AC circuit shown in Figure, where a resistance $R$, a capacitance $C$, and an inductance $L$ are connected in series, is $I=\frac{\mathcal{E}}{R}$. What will be the current in the AC circuit when the inductance and the capacitance connected in parallel are connected in series with the resistance (Figure)?

The power in an AC circuit varies with time according to the curve in the figure. How, knowing the maximal and minimal values of the power, to determine the numerical value of the phase shift between voltage and current? What is the period of variation of the power?