Context: Another extreme case of impedance matching occurs when using a small loop antenna (usually, but not always, for receiving) at a relatively low frequency where it appears almost as a pure inductor. Resonating such an inductor with a capacitor at the frequency of operation not only cancels the reactance but greatly magnifies the very small radiation resistance of such a loop.[citation needed] This is implemented in most AM broadcast receivers, with a small ferrite loop antenna resonated by a capacitor which is varied along with the receiver tuning in order to maintain resonance over the AM broadcast band

Question: What magnifies the small radiation resistance of a loop?
Answer: a capacitor at the frequency of operation

Question: What is used in most AM broadcaster receivers?
Answer: loop

Question: What is resonated by a capacitor along with the receiver tuning that maintains resonance over the AM broadcast band?
Answer: small ferrite loop antenna

Question: When using a small loop antenna at a low frequency, what may occur?
Answer: impedance matching