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PHYS Final t/f
PHYS Final
Question | Answer |
---|---|
Sound is an example of a transverse wave. | False |
The DISTANCE between adjacent pressure peaks of a sound wave is known as a PERIOD. | False |
The velocity of sound in air depends on the temperature of the air and is larger for higher temps. | True |
For wind instruments, to DECREASE the lowest note normally played by an octave, one must INCREASED the overall length of the instrument by a factor of two. | True |
The distance between the frets of a guitar get smaller as you move away from the end with the tuning pegs(the nut) and toward the bridge. | True |
The f-holes on a violin are designed with the Helmholtz resonance in mind. | True |
Sound generally travels faster in a gas than in a solid. | False |
The maximum displacement from either side of the equilibrium position in simple harmonic motion known as the amplitude. | True |
If the frequency of middle C on the piano is 262 Hz, then the frequency of the C two octaves above middle C must be 1048 Hz. | True |
Increasing the area of the sound hole in a guitar would tend to decrease the Helmholtz resonant frequency of the guitar | False |
Strong diffraction occurs when the wave length is about the same size or larger than the width of the opening or obstacle. | True |
For the purposes of scientific classification, a trumpet could be considered a double reed instrument. | True |
The law of reflection states that the angle of incidence is equal to the angle of reflection. These angles are measured relative to the normal (or perpendicular ) to the interface. | True |
A xylophone bar is thinned on the underside of the bar (in the middle) to lower the fundamental frequency relative to the second mode frequency in order to make the ratio f2/f1=3. | True |
Kinetic energy is the energy of motion. | True |
If two sources of sound of equal frequency combine at a point so that the path difference L1-L2 is an integer number of wavelengths, DESTRUCTIVE interference occurs. | False |
The law of reflection can explain how a "whispering gallery" works. | True |
Ultrasonic sound has a frequency lower than what a normal human can hear. | False |
For a mass on a spring, the PERIOD of oscillation depends on size (amplitude ) of the oscillation. | False |
Most musical instruments obey the general rule that frequency is inversely proportional to the length. | True |
The psychological variable loudness depends ONLY on the physical variable intensity and not frequency or waveform. | False |
An increase in SIL of 10 dB would b perceived as roughly a doubling of the loudness for most people. | True |
The attack and decay parts of the waveform are often important for musical instrument identification. | True |
Any periodic waveform of period T can be built from a series of sine waves whose frequencies form a harmonic series with fundamental frequency f1=1/T | True |
Any non-periodic waveform can be built from a series of sine waves, but the frequencies will not belong to a harmonic series. | True |
The DIFFERENCE in frequency between adjacent semitones is always the same | False |
Olms law (for acoustics, not resistors) states that for steady sounds, the relative phases between the sine waves making up a complex are NOT important in our perception of tone color or timbre. | True |
The sound intensity level of two instruments playing a duet is simply the sum of the individual SIL of each instrument playing solo. | False |
The just noticeable difference(JND) in the case of of sound intensity level is roughly 5 dB under most conditions. | False |
Sound that lasts for short amounts of time can have a smaller perceived loudness than continuous of the same intensity. | True |
The pain threshold of sound intensity level is at 120 dB, Ant SIL above this is sounds painfully loud. | True |
Suppose you change a sine wave's frequency from 150 Hz to 400 Hz and then again from 400 Hz to 650 Hz. The first interval would be heard as more than an octave and the second interval would be heard as less than an octave. | True |
The SI unit of power is Watts(W) , which is the same as joule/second | True |
The 4th harmonic of the fundamental frequency 200 Hz would be 400 Hz | False |
The missing fundamental effect is the observation that given a harmonic series with many harmonies present except a missing fundamental f1,one hears the same pitch that one would if the fundamental was not missing. | True |
The ear is most sensitive to sounds around 3500 Hz due to the fact that a quarter wavelength of sound at this frequency fits inside the auditory canal and resonates. | True |
White noise is a term indicating roughly equal amplitudes of all frequencies in the fourier spectrum. | True |
The bones in the middle ear acts as a lever system increasing the force(and pressure) acting on the oval window. | True |
Sounds with identical Fourier spectra must have identical waveform shapes on the oscilloscope. | False |
The semicircular canals in the ear do not participate in sound detection, but instead are involved in one's sense of balance and detection of head motion. | True |
A xylophone bar is thinned in the center to make the second natural mode frequency to be two octaves above the fundamental frequency (f2/f1=4) | False |
The f-holes on a violin are just for decoration and don't affect the sound of the instrument compared to if they were not present at all. | False |
The pitch you hear from a tympani relies on the missing fundamental effect and this fundamental frequency is not present in the spectrum. | True |
The "clang" tone of a tuning fork corresponds to the second mode of vibration of a bar clamped at one end which has a node near the end of the bar. | True |
A cello bow excite string vibrations using the stick-slip mechanism. | True |
In general, high frequency modes of vibration die out at a SLOWER rate than low frequency modes of vibration. | False |
the bridge of the violin transmits the string vibrations to the body of the violin. | True |
Two masses connected by springs on a two-dimensional air hockey table would have a total of 2 degrees of freedom. | false |
For an edge tone organ pipe, harmonics higher than the critical mode number nc=L/D are much less prominent in the fourier spectra. | True |
The pickups nearest the bridge of an electric guitar emphasize the fundamental mode of vibration and deemphasizes the higher harmonics. | False |
Nylon strings on an electric guitar would not work since they are not magnetic. | True |
The FORMANT frequencies of a sung pure vowel depend only the tension of the vocal cords. | True |
The word "plosive" starts with an unvoiced plosive. | True |
The word "fricative" starts with a voiced fricative. | False |
The lower pitched strings on a guitar are wound with wire to increase the linear mass density of the string without much increasing the stiffness of the string. | True |
Since the clarinet is a woodwind instrument that is essentially a cylindrical tube closed at one end,generally only the odd harmonics are prominent in its Fourier spectrum(especially in its lowest register) | True |
The timbre of a guitar does not change when the plucking location along the string is varied. | False |
There is a pressure node at the open end of a cylindrical pipe and a pressure anti-node at the closed end of a cylindrical pipe. | True |
There is a displacement node at the open end of a cylindrical pipe and a displacement antinode at the closed end of a cylindrical pipe. | False |
A vibrating circular membrane has modes with both nodal diameters and nodal circles. | True |