What is the effect of installing a single inductor in series between an amplifier's positive speaker output and the speaker?

Installing a single inductor in series between an amplifier's positive speaker output and the speaker creates a high-pass filter effect. An inductor has the property of opposing changes in current, which means that at lower frequencies, it will resist the flow of current more than it does at higher frequencies. As a result, low-frequency signals are attenuated or cut off, while higher-frequency signals can pass through more easily.

This high-pass filtering effect is fundamental in speaker design, particularly for protecting tweeters from potentially damaging low-frequency signals. The inductance value determines the frequency at which the cutoff occurs; larger inductance values will result in a lower cutoff frequency, allowing for more bass frequencies to pass, while smaller inductance values will cut off more low frequencies sooner.

Therefore, the correct answer accurately describes the role of the inductor in restricting the low-frequency signals to the speaker, effectively allowing high frequencies to be reproduced while attenuating the low frequencies.