Question

Why inductors are not preferred for audio frequency?

(a) Large and heavy

(b) High power dissipation

(c) High input impedance

(d) None of the mentioned

The question was posed to me during an interview.

Enquiry is from Active Filters topic in section Active Filters of Linear Integrated Circuits

Answer 1

The correct answer is:

(a) Large and heavy

Explanation:

Inductors are generally not preferred for audio frequencies due to the following reasons:

• (a) Large and heavy: Inductors can become large and bulky at audio frequencies because their inductance value needs to be high enough to filter out unwanted frequencies. For audio applications, where frequencies range from 20 Hz to 20 kHz, large inductors are required, making them less practical and heavy for integration into compact circuits.

Why the other options are incorrect:

• (b) High power dissipation: Inductors typically have low power dissipation compared to resistive components. Therefore, power dissipation is not a significant issue for inductors at audio frequencies.

• (c) High input impedance: Inductors at audio frequencies generally do not have a particularly high input impedance. In fact, they present an inductive reactance that depends on the frequency of the signal. This makes inductors less suitable for audio applications, but not because of high input impedance.

• (d) None of the mentioned: Since (a) is the correct answer, this option is not applicable.

Thus, (a), "Large and heavy," is the correct reason why inductors are not preferred for audio frequency applications.