Gibilisco: MCQ in Acoustics, Audio, and High Fidelity | ECE Board Exam

This is the Multiple Choice Questions (MCQs) in Chapter 31: Acoustics, Audio, and High Fidelity from the book Teach Yourself Electricity and Electronics, 5th edition by Stan Gibilisco. If you are looking for a reviewer in Electronics Engineering this will definitely help you before taking the Board Exam.

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Choose the letter of the best answer in each questions.

1. Acoustics is important in the design of:

A. Amplifier power supplies.

B. Speaker enclosures.

C. Cables that connect components of a hi-fi system together.

D. Graphic equalizers.

2. Electromagnetic interference to a hi-fi amplifier can be caused by:

A. A nearby radio broadcast station.

B. Improperly designed receiving antennas.

C. Excessive utility voltage.

D. Improper balance between the left and right channels.

3. The midrange audio frequencies:

A. Are halfway between the lowest and highest audible frequencies.

B. Represent sounds whose volume levels are not too loud or too soft.

C. Are above the treble range but below the bass range.

D. Are between approximately 0.2 and 2 kHz.

4. An indoor concert hall such that sound reaches every listener’s ears perfectly at all audio frequencies requires:

A. A suspended ceiling with acoustical tile completely covering it.

B. Numerous baffles on the walls and ceiling.

C. A level of engineering beyond reasonable expectation.

D. Avoidance of excessive background noise.

5. A sound volume change of -3 dB represents:

A. A doubling of acoustic power.

B. A threefold increase in acoustic power.

C. A tenfold increase in acoustic power.

D. No change in acoustic power.

6. A sound whose wavelength is 6in in the air has a frequency of:

A. 550 Hz.

B. 1100 Hz.

C. 2200 Hz.

D. It is impossible to calculate from this information.

7. A sound wave that travels at 335 m per second has a frequency of:

A. 335 Hz.

B. 3350 Hz.

C. 33.5 Hz.

D. It is impossible to calculate from this information.

8. The relative phase of two acoustic waves, as they arrive at your ears, can affect:

A. How loud the sound seems.

B. The direction from which the sound seems to be coming.

C. Both A and B.

D. Neither A nor B.

9. In an acoustic sine wave:

A. The frequency and phase are identical.

B. The sound power is inversely proportional to the frequency.

C. The sound power is directly proportional to the frequency.

D. All of the sound power is concentrated at a single frequency.

10. Vinyl disks are:

A. Susceptible to physical damage.

B. Useful primarily in high-power sound systems.

C. Digital media.

D. Preferred for off-the-air sound recording.

11. If an amplifier introduces severe distortion in the waveforms of input signals, then that amplifier is:

A. Not delivering enough power.

B. Operating at the wrong frequency.

C. Operating in a nonlinear fashion.

D. Being underdriven.

12. If a 10-watt amplifier is used with speakers designed for a 100-watt amplifier:

A. The speakers are capable of handling the amplifier output.

B. The amplifier might be damaged by the speakers.

C. Electromagnetic interference is likely to occur.

D. The speakers are likely to produce distortion of the sound.

13. Which of the following frequencies cannot be received by an AM/FM tuner?

A. 830 kHz.

B. 95.7 kHz.

C. 100.1 MHz.

D. 107.3 MHz.

14. A woofer:

A. Is especially useful for reproducing the sounds of barking dogs.

B. Is designed to handle short, intense bursts of sound.

C. Should not be used with a graphic equalizer.

D. Is designed to reproduce low-frequency sounds.

15. Suppose you have an amateur radio station and its transmitter causes EMI to your hi-fi system. Which of the following would almost certainly not help?

A. Buy a radio transmitter that works on the same frequencies with the same power output, but is made by a different manufacturer.

B. Reduce the transmitter output power.

C. Use shielded speaker wires in the hi-fi system.

D. Move the radio transmitting antenna to a location farther away from the hi-fi system.

16. A tape recording head:

A. Converts sound waves to radio signals.

B. Converts sound waves to fluctuating electric current.

C. Converts audio-frequency currents to a fluctuating magnetic field.

D. Converts direct current to audio-frequency currents.

17. A microphone:

A. Converts sound waves to radio signals.

B. Converts sound waves to fluctuating electric current.

C. Converts audio-frequency currents to a fluctuating magnetic field.

D. Converts direct current to audio-frequency currents.

18. An audio mixer:

A. Cannot match impedances.

B. Cannot make an amplifier more powerful.

C. Will eliminate EMI.

D. Allows a microphone to be used as a speaker.

19. Which of the following media or devices use digital-to-analog conversion?

A. A CD player.

B. A speaker.

C. A microphone.

D. A vinyl disk.

20. Phase quadrature is sometimes used to:

A. Increase the output from a microphone.

B. Reduce the susceptibility of a hi-fi system to EMI.

C. Create the illusion of four-channel stereo when there are really only two channels.

D. Convert an analog signal to a digital signal, or vice-versa.

Topics Included in the Test from Chapter 31 to Chapter 34

Complete List of Multiple Choice Questions from this Book

Check your work.