Physics Homework 3 Fall 2015 Exam Name

Transcription

1 Exam Name MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Which of the following is the limiting frequency that a DVD can sample and reproduce? 1) A) 5 khz, B) 44.1 khz. C) 17 khz, D) 22 khz, E) 15 khz, 2) Which of the following converts sound signals into electrical signals? 2) A) microphone. B) power amplifier, C) preamplifier, D) speaker, E) signal source, 3) Which are true? 3) A) This shell needs to be circular or parabolic in shape. B) In order to obtain fullness in an open-air amphitheater, it is necessary to provide a shell over the performers. C) If there is a rear wall to the amphitheater, it should be made of reflective material in order to reduce echoes. 4) Which of the following is a measure of how difficult it is for alternating current to flow through a circuit? 4) A) impedance, B) voltage, C) power. D) resistance, E) current, 5) Which of the following is designed primarily to produce low frequency sounds? 5) A) tweeter, B) acoustic suspension speaker, C) woofer. D) tuned-port speaker, E) infinite baffle, 6) Which of the following frequencies is the U.S. standard value of A used today when setting the standard pitch level for musical scales? 6) A) 440 Hz, B) 435 Hz, C) 256 Hz, D) 415 Hz, E) 1000 Hz. 7) Which of the following is a room with walls that absorb sound almost completely? 7) A) instant people, B) open-air auditorium, C) indoor hall

2 D) adding or changing surface coatings, E) anechoic chambers, 8) Which of the following is the MKS unit of measurement for electrical current? 8) A) watts, B) amperes, C) joules. D) ohms, E) volts, 9) Which of the following types of harmony is most commonly used in a duet? 9) A) monophonic structure, B) four-parts, C) tonic. D) two-parts, E) three-parts, 10) Which of the following refers to tuning the rest of the octaves of a musical scale after the first octave has been tuned properly? 10) A) comma of Didymus, B) setting the temperament, C) fixing the frequencies. D) wolf fifth, E) comma of Pythagoras, 11) Which of the following arrives at the listener first? 11) A) direct sound B) reverberation time C) reflected sound D) More than one of these E) None of these. 12) High-quality preamplifiers need to control their linearity over the entire audible range within 1 db in order to stay within which of the following properties of hearing? 12) A) VU, B) CD. C) JND, D) IMD, E) THD, 13) Which of the following is the opposite of warmth and exists if the reverberation time for high frequencies is larger relative to that of the low frequencies? 13) A) brilliance, B) texture, C) clarity, D) blend, E) ensemble. 14) Which of the following refers to the amount of reflected sound intensity relative to the intensity of the direct sound? 14) A) intimacy B) liveness C) warmth - 2 -

3 D) fullness E) None of these. 15) Which of the following sound better in some keys but worse in other keys? 15) A) open temperament, B) closed unequal temperament, C) equal temperament, 16) Which are true? 16) A) The only true interval in the equal-tempered scale is the octave. B) The interval between a half-step on an equal-tempered scale is the twelfth-root of two or C) Most people with a moderate ear for music can tell the difference between music played in the equaltempered scale and that played the purer sound of the Werckmeister scale in its good keys 17) Which of the following scales allows music to sound equally good in any and all keys? 17) A) Pythagorean scale B) just diatonic natural minor scale, C) just diatonic major scale, D) just scale, E) equal-tempered scale. 18) Which of the following problems in acoustical design are a consequence of nearby airports, railroads, and highways? 18) A) shadows, B) focusing, C) resonance, D) external noise. E) echoes, 19) Which of the following contains twelve musical intervals, each with a frequency ratio of 3:2? 19) A) pitch level, B) temperament, C) circle of fifths. D) chromatic scale, E) major scale, 20) Which of the following is used to switch a single digital track into two separate tracks in order to reproduce two stereo channels of music? 20) A) DA converter, B) multiplexer. C) AD converter, D) DVD, - 3 -

4 E) CD, 21) Which are true? 21) A) Most, if not all, professional piano tuners believe that the use of an electronic tuner will yield better high quality tuning than can be obtained by a well-trained craftsman using the ear alone. B) Modern digital synthesizers can only play music in the equal tempered scale, they cannot be programmed to play in other temperaments. C) Inexpensive and easy-to-use electronic tuners have spawned a whole generation of do-it-yourself piano tuners. 22) Which of the following musical intervals has a frequency ratio of 4:3? 22) A) major third, B) fourth, C) octave. D) minor third, E) fifth, 23) Which of the following is the symbol used for the unit of measurement for work and energy? 23) A) V, B) J, C) A, D) I, E) W. 24) Which of the following factors is most critical when it comes to the electronic aspect of a good stereo sound system in a home entertainment center? 24) A) quality of audio components, B) the size and shape of the room, C) loudspeaker placement, D) the type of material used in the various surfaces, E) More than one of these. 25) Which of the following controls on a preamplifier is used to boost those frequencies that the ear is less sensitive to when playing soft background music? 25) A) balance, B) volume, C) selection. D) tone, E) loudness, 26) Which of the following is an open temperament that distributes all of its tuning errors into a single location on its scale? 26) A) Werckmeister temperament. B) Pythagorean temperament, C) just temperament, D) quarter-comma mean-tone temperament, E) Valotti temperament, - 4 -

5 27) Which are true? 27) A) Noise that falls off in power per unit frequency at the rate of 3 db per octave is called pink noise. B) Modern equalizer circuits have provided us with a convenient way of tuning our listening rooms by removing any strong resonances that may emphasize certain frequencies. C) In order to fill a normal home listening room with sound, less than 100 W of acoustical power is required. ( 28) The intensity level of sound drop away from walls, ceiling, or floor (for instance, up in the sky) will decrease by how much when the distance between source and listener doubles? 28) A) 6 db, B) 9 db, C) 12 db D) 18 db. E) 3 db, 29) Which of the following uses a focusing reflector to concentrate the sound? 29) A) parabolic microphone, B) shotgun microphone, C) cardioid microphone, D) omnidirectional microphone, E) More than one of these. 30) Which are true? 30) A) Flutter echoes are most pronounced when the two side walls of an auditorium are highly reflective and parallel. B) Long overhanging balconies and other structures jutting into an auditorium are the primary source of resonance. C) Air conditioners and blowers are often the sources of white noise or noise rich in lower frequencies which can mask out the higher-frequency sounds of the music