**Category:** Electromagnetism  
**Subtype:** AC Circuits  
**Problem Description:** This problem involves analyzing an AC circuit with resistors, inductors, and capacitors. It requires determining the effective voltage \(U\) applied across a series circuit consisting of a resistor (between points A and M), an inductor (between points M and N), and a capacitor (between points N and B). The problem states that the power consumed in the resistor section (AM) is equal to the power consumed in the inductor section (MN). The instantaneous voltage across specific points is provided in a graph, and the task is to approximate the value of \(U\) from the given options.