The correct answer is A. Radio frequency.
A tuned amplifier is an amplifier that is designed to amplify a specific frequency or range of frequencies. It does this by using a tuned circuit, which is a circuit that resonates at a specific frequency. The tuned circuit is used to select the desired frequency or range of frequencies, and the amplifier then amplifies the selected frequencies.
Tuned amplifiers are
used in a variety of applications, including radio receivers, transmitters, and amplifiers. They are also used in some types of test equipment.A tuned amplifier is not used in low frequency applications because the tuned circuit would be too large and bulky. A tuned amplifier is also not used in audio frequency applications because the tuned circuit would be too sensitive to noise.
Here is a brief explanation of each option:
- Option A: Radio frequency. A tuned amplifier is used in radio frequency applications because it can amplify a specific frequency or range of frequencies.
- Option B: Low frequency. A tuned amplifier is not used in low frequency applications because the tuned circuit would be too large and bulky.
- Option C: Audio frequency. A tuned amplifier is not used in audio frequency applications because the tuned circuit would be too sensitive to noise.
- Option D: None of the above. This option is incorrect because a tuned amplifier is used in radio frequency applications.