text: The impedance caused by these devices is directly proportional to the frequency.
full_question: The impedance caused by these devices is directly proportional to the frequency. One of these devices designed to block alternating current from passing is called a choke. The energy stored in these systems is proportional to "one half current squared" times a namesake quantity. Two of these devices are used in transformers. The behavior of these circuit elements is described by Faraday's law. On circuit diagrams, these devices are depicted as coils. These devices generate a magnetic field when current passes through them. For 10 points, name these circuit elements whose namesake quantity is symbolized L and is measured in Henries.
first_sentence: The impedance caused by these devices is directly proportional to the frequency.
raw_answer: inductors [or inductance; prompt on solenoids]