1.
Which of these things does NOT characterize a sound?
Correct Answer
A. It is periodic
Explanation
Chapter 1; Simple Harmonic Motion and Pure Tones
2.
What is the simplest of all sound waves?
Correct Answer
pure tone
Explanation
A pure tone is the simplest form of a sound wave. It is a sound wave that has a single frequency and no harmonics or overtones. Unlike complex sound waves that are made up of multiple frequencies, a pure tone has a uniform waveform and produces a clear, single pitch. This simplicity makes it easier to analyze and understand the properties of sound waves.
3.
Number of cycles in a given second is known as:
Correct Answer
B. Frequency
Explanation
The number of cycles in a given second is known as frequency. Frequency is a measure of how many complete cycles of a wave occur in a given time period. It is usually measured in hertz (Hz), which represents the number of cycles per second. Wavelength refers to the distance between two corresponding points on a wave, velocity is the speed at which a wave travels, and amplitude is the maximum displacement of a wave from its equilibrium position.
4.
The decrease in the amplitude of displacement over time:
Correct Answer
damping
Explanation
Damping refers to the decrease in the amplitude of displacement over time. It occurs when a system or object experiences resistance or friction, causing it to lose energy and gradually reduce its oscillation or vibration. This can be observed in various physical systems, such as a swinging pendulum or a vibrating spring, where the motion gradually slows down and comes to rest due to the dissipation of energy. Damping is an essential concept in engineering and physics, as it helps control and stabilize oscillatory systems.
5.
Amplitude-by-time graph is
Correct Answer
wave form, waveform
Explanation
The term "amplitude-by-time graph" refers to a graphical representation of a wave's amplitude over time. It shows how the amplitude of the wave changes as time progresses. This graph is commonly referred to as a "waveform" or "wave form" as it visually depicts the shape and characteristics of the wave.
6.
The period of vibration is the time taken for each cycle.
Correct Answer
A. True
Explanation
The statement is true because the period of vibration refers to the time it takes for one complete cycle of vibration to occur. It is a measure of the time it takes for an object to complete one full oscillation or back-and-forth motion. Therefore, the period of vibration is indeed the time taken for each cycle.
7.
The graphical representation of the movement of a body vibrating in simple harmonic motion.
Correct Answer
sine wave
Explanation
The graphical representation of the movement of a body vibrating in simple harmonic motion is called a sine wave. A sine wave is a smooth, repetitive oscillation that can be represented by a mathematical function known as the sine function. In simple harmonic motion, the body moves back and forth in a periodic manner, with its displacement from the equilibrium position following a sine wave pattern. The amplitude of the wave represents the maximum displacement of the body, while the period represents the time taken for one complete oscillation. Therefore, a sine wave accurately represents the movement of a body in simple harmonic motion.
8.
A waveform is often scaled in units of frequency and amplitude.
Correct Answer
B. False
Explanation
amplitude and time
9.
A vibration that repeats itself in EXACTLY the same way is:
Correct Answer
periodic
Explanation
A vibration that repeats itself in exactly the same way is called periodic. This means that the vibration follows a pattern and occurs at regular intervals. The term "periodic" implies that the vibration has a consistent and predictable behavior, allowing it to be repeated in the same manner over time.
10.
What force(s) result in the back and forth movement of an object?
Correct Answer(s)
B. Elasticity
D. Inertia
Explanation
The back and forth movement of an object is caused by the forces of elasticity and inertia. Elasticity refers to the ability of an object to return to its original shape after being stretched or compressed. When an object is deformed and then released, it undergoes oscillatory motion, moving back and forth due to the force of elasticity. Inertia, on the other hand, is the tendency of an object to resist changes in its state of motion. Once an object is set into motion, it will continue to move back and forth until acted upon by an external force, due to its inertia.
11.
An object in motion will stay in motion; an object at rest will stay at rest (unless otherwise acted upon)
Correct Answer(s)
inertia
Explanation
This statement is known as Newton's first law of motion and it describes the concept of inertia. Inertia is the tendency of an object to resist changes in its motion. If an object is already in motion, it will continue to move at a constant velocity unless an external force acts upon it. Similarly, if an object is at rest, it will remain at rest unless acted upon by an external force. Inertia is a fundamental property of matter and is responsible for various phenomena in the physical world.
12.
The tendency of matter to recover from distortion of shape or volume.
Correct Answer(s)
elasticity
Explanation
Elasticity refers to the ability of a material to regain its original shape or size after being deformed. When matter is subjected to a distortion in its shape or volume, it has a natural tendency to bounce back and return to its original form. This property is known as elasticity.
13.
Elasticity and inertia work simultaneously in the same direction.
Correct Answer
B. False
Explanation
They work simultaneously but in opposite directions. Elasticity causes a decrease in the velocity of movement as the point of maximum displacement is being approached.
14.
Changes in amplitude will change the frequency of the wave.
Correct Answer
B. False
Explanation
Frequency remains the same though the amplitude dampens. Think of the swing analogy from lecture (1/18).
15.
During condensation:
Correct Answer
C. There is a rush of pressure
Explanation
During condensation, a gas or vapor is converted into a liquid state. This process occurs when the temperature of the gas or vapor decreases, causing the molecules to lose energy and come closer together. As the gas molecules condense into a liquid, they occupy a smaller volume, resulting in a higher density. This increase in density leads to a rush of pressure, as the molecules are now packed more closely together. Therefore, the correct answer is "there is a rush of pressure."
16.
During rarefaction:
Correct Answer
A. There is a lack of pressure
Explanation
During rarefaction, there is a lack of pressure. Rarefaction refers to the reduction in the density or pressure of a medium, such as air or a gas. It occurs when the particles in the medium are spread out, resulting in a decrease in the number of collisions between particles and a decrease in the overall pressure. This is in contrast to compression, where the particles are closer together and the pressure is higher. Therefore, during rarefaction, there is a decrease or lack of pressure.
17.
Type of wave characterized by particle movement being parallel to the wave movement.
Correct Answer
longitudinal, longitudinal wave
Explanation
A longitudinal wave is a type of wave where the particles of the medium move parallel to the direction of wave propagation. In other words, the displacement of particles in a longitudinal wave is in the same direction as the wave itself. This is in contrast to a transverse wave, where the particles move perpendicular to the wave direction. Therefore, "longitudinal" and "longitudinal wave" are the correct answers to describe this type of wave characterized by parallel particle movement to the wave movement.
18.
Type of wave characterized by particle movement that is perpendicular to wave movement.
Correct Answer
transverse, transverse wave
Explanation
A transverse wave is a type of wave in which the particles of the medium vibrate perpendicular to the direction of wave propagation. In other words, the particles move up and down or side to side as the wave travels forward. This is in contrast to a longitudinal wave, where the particles move parallel to the direction of wave propagation. Therefore, the term "transverse" accurately describes the type of wave characterized by particle movement that is perpendicular to wave movement. The repetition of the term "transverse wave" in the answer emphasizes the correctness of this description.
19.
Frequency remains constant through damping.
Correct Answer
A. True
Explanation
This statement is true because damping refers to the reduction of oscillation or vibration over time. In a system with damping, the amplitude of the oscillation decreases, but the frequency remains constant. This means that even though the oscillation may become smaller and eventually stop, the rate at which it occurs remains the same. Therefore, the frequency remains constant through damping.
20.
When one signal is one fourth of a cycle ahead of the other they can be considered:
Correct Answer
C. 90 degrees out of pHase
Explanation
When two signals are considered to be "out of phase," it means that they are not perfectly synchronized and have a phase difference between them. In this case, when one signal is one fourth of a cycle ahead of the other, it means that they are 90 degrees out of phase. This indicates that the two signals are not aligned and have a phase difference of one-fourth of the total cycle.
21.
If waves are combined that are 180 degrees out of phase the amplitude of the resulting wave will be twice as high as its components.
Correct Answer
B. False
Explanation
The two waves will cancel one another because they are moving at the same rate in opposite directions
22.
The property of waves to add up (superpose) constructively or destructively.
Correct Answer
interference
Explanation
Interference refers to the property of waves to add up constructively or destructively. When two or more waves meet, they can either reinforce each other, resulting in constructive interference, or cancel each other out, resulting in destructive interference. This phenomenon is observed in various wave systems, such as light waves, sound waves, and water waves. Interference plays a crucial role in many applications, including noise cancellation, optical imaging, and the study of wave behavior.
23.
A doubling of the frequency results in a(n)
Correct Answer
octave
Explanation
When the frequency of a sound wave is doubled, it results in an octave. An octave refers to a musical interval between two notes where the higher note has a frequency that is exactly double the frequency of the lower note. This means that when the frequency is doubled, the pitch of the sound also increases by an octave. In music, octaves are often used to create harmonies and add depth to the overall sound.
24.
Random variations of sound pressure can be considered.
Correct Answer
aperiodic
Explanation
Random variations of sound pressure can be considered aperiodic because the term "aperiodic" refers to something that lacks a regular or repeating pattern. In the context of sound, aperiodic variations in sound pressure occur when the fluctuations in pressure do not follow a consistent or predictable pattern. This can happen in situations where the sound source is irregular or when there is noise or interference present. Therefore, the term "aperiodic" accurately describes the random variations of sound pressure mentioned in the question.
25.
Anything that is not simple harmonic.
Correct Answer
complex sound
Explanation
Anything that is not simple harmonic refers to any sound that does not follow the pattern of simple harmonic motion. Simple harmonic motion refers to a type of motion where the restoring force is directly proportional to the displacement from equilibrium. Complex sound, on the other hand, refers to a sound wave that is composed of multiple frequencies and does not exhibit simple harmonic motion. Therefore, complex sound is the correct answer as it encompasses any sound that is not simple harmonic.
26.
Decomposition of complex signal into multiple simple waves is known as:
Correct Answer
Fourier Analysis, fourier analysis, Fourier analysis
Explanation
The process of decomposing a complex signal into multiple simple waves is known as Fourier analysis. This technique allows us to analyze and understand the different frequency components present in a signal. By breaking down the signal into its constituent waves, we can study their individual properties and how they contribute to the overall signal. Fourier analysis is widely used in various fields, including signal processing, image analysis, and communication systems.
27.
The full set of harmonics is known as the harmonic series.
Correct Answer
A. True
Explanation
The full set of harmonics refers to the collection of all frequencies that are integer multiples of the fundamental frequency. This collection is called the harmonic series. Therefore, the statement "The full set of harmonics is known as the harmonic series" is true.
28.
The sensation associated with frequency.
Correct Answer
pitch
Explanation
Pitch is the term used to describe the sensation associated with frequency. It refers to how high or low a sound is perceived to be. When the frequency of a sound wave is high, the pitch is perceived as high, and when the frequency is low, the pitch is perceived as low. Pitch is an important aspect of music and is used to distinguish between different notes and tones.
29.
Listeners asked to judge pitch will compensate for a missing fundamental frequency.
Correct Answer
A. True
Explanation
Listeners asked to judge pitch will compensate for a missing fundamental frequency. This statement is true because when a fundamental frequency is missing from a sound, listeners are still able to perceive the pitch of the sound by relying on the harmonics or overtones present in the sound. The brain is able to fill in the missing fundamental frequency based on the relationship between the harmonics, allowing listeners to accurately judge the pitch of the sound.
30.
The sensation of judged intensity.
Correct Answer
loudness
31.
The scaling unit of measure for loudness.
Correct Answer
sone
Explanation
The sone is a unit of measure for loudness. It quantifies the subjective perception of sound intensity by an average listener. The sone scale is based on the loudness level of a 1,000 Hz tone at a specific sound pressure level. It allows for the comparison of different sounds in terms of their perceived loudness.
32.
The units of loudness are:
Correct Answer
phons, phon
Explanation
The units of loudness are phons and phon. These units are used to measure the perceived loudness of sound. The phon is a unit of loudness level that is based on the equal loudness contours of the human ear. It represents the sound pressure level of a pure tone at a frequency of 1,000 Hz that is perceived as equally loud as the sound being measured. The phons, on the other hand, are used to measure the loudness of complex sounds and take into account the frequency content of the sound.
33.
The distance in space that one cycle occupies is:
Correct Answer
D. Wavelength
Explanation
The distance in space that one cycle occupies is referred to as the wavelength. It represents the length between two consecutive points of a wave that are in phase. In other words, it is the distance from one peak to the next or from one trough to the next. Amplitude, frequency, and intensity are all important properties of a wave, but they do not directly describe the distance in space that one cycle occupies.
34.
What is the perceptual dimension of amplitude?
Correct Answer
B. Loudness
Explanation
The perceptual dimension of amplitude refers to the intensity or strength of a sound wave. It is commonly associated with the perception of loudness. Loudness is a subjective measure of how loud or soft a sound is perceived to be by an individual. It is influenced by the physical amplitude of the sound wave, as well as factors such as distance from the sound source and individual hearing abilities. Therefore, in the context of this question, the correct answer is loudness.
35.
What is the physical dimension for a pitch?
Correct Answer
D. Frequency
Explanation
The physical dimension for a pitch is frequency. Pitch refers to the perceived highness or lowness of a sound, which is determined by the frequency of the sound wave. Frequency is the number of cycles or vibrations per second and is measured in Hertz (Hz). Different frequencies create different pitches, with higher frequencies resulting in higher pitches and lower frequencies resulting in lower pitches. Therefore, frequency is the correct answer for the physical dimension of a pitch.
36.
The perception of how 'low' or 'high' a sound is perceived.
Correct Answer
pitch
Explanation
The term "pitch" refers to the perception of how high or low a sound is. It is a subjective measure of the frequency of a sound wave, with higher frequencies being perceived as higher pitches and lower frequencies being perceived as lower pitches. Therefore, in the given context, "pitch" accurately describes the perception of the sound's "low" or "high" quality.
37.
The force exerted by air mass on an area.
Correct Answer
pressure
Explanation
Pressure is defined as the force exerted by a fluid, such as air, on a given area. In this context, the correct answer refers to the force exerted by the air mass on a specific area. Pressure is a fundamental concept in physics and is commonly used to describe various phenomena, such as weather systems, fluid dynamics, and even the behavior of gases. Therefore, pressure is the appropriate term to describe the force exerted by an air mass on an area.
38.
The rate at which energy is transferred over an area.
Correct Answer
intensity
Explanation
The term "intensity" refers to the rate at which energy is transferred over an area. It represents the strength or power of a particular phenomenon, such as sound, light, or radiation. In other words, intensity measures how concentrated or focused the energy is in a given space. It is often used to describe the brightness of light or the loudness of sound, indicating the amount of energy per unit area. Therefore, intensity is the correct answer for the given explanation.
39.
If the intensity of one sound is 1000 times greater than another sound's intensity, what is the difference in decibels?
Correct Answer
D. 30 dB IL
Explanation
The answer 30 dB IL is correct because the question asks for the difference in decibels between two sounds with different intensities. The IL (Intensity Level) is a logarithmic scale used to measure the intensity of sound. A difference of 30 dB IL means that the sound with greater intensity is 1000 times louder than the sound with lower intensity.
40.
If the pressure of one sound is 1000 times greater than another sound's pressure, what is the difference in decibels?
Correct Answer
60 dB SPL
Explanation
The difference in decibels between two sounds is determined by the ratio of their sound pressures. In this case, if one sound has a pressure that is 1000 times greater than the other sound, the ratio of their pressures is 1000:1. To calculate the difference in decibels, we use the formula: dB = 20 * log10(p1/p0), where p1 is the pressure of the first sound and p0 is the reference pressure (usually 20 micropascals). By substituting the values into the formula, we find that the difference in decibels is 60 dB SPL.
41.
How much greater (in pressure) than a minimally audible sound is a 100 dB SPL sound?
Correct Answer
100,000 times greater in pressure, 100000 times greater in pressure
Explanation
100 dB SPL= 20 log(x)
100/20= 5 therefore,
5=log(x)
10 raised to 5= 100,000
42.
How much greater (in intensity) than a minimally audible sound is a 100 dB IL sound?
Correct Answer
10,000,000,000 times greater in intensity, 10000000000 times greater in intensity
Explanation
A 100 dB IL sound is 10,000,000,000 times greater in intensity than a minimally audible sound. This means that the 100 dB IL sound is extremely loud and intense compared to the barely audible sound.
43.
The measure of 'equal loudness"
Correct Answer
phon
Explanation
The measure of "equal loudness" is called a phon. A phon is a unit used to quantify the perceived loudness of sound by taking into account the sensitivity of the human ear at different frequencies. It allows for a more accurate representation of how loud a sound is perceived by the average human listener.
44.
The measure of 'relative loudness'
Correct Answer
sone
Explanation
The measure of 'relative loudness' is called sone. Sone is a unit used to quantify the perceived loudness of sound by the human ear. It takes into account factors such as frequency and intensity of sound waves. The higher the sone value, the louder the sound is perceived to be.
45.
0 dB is an absence of sound.
Correct Answer
B. False
Explanation
The statement "0 dB is an absence of sound" is false. In acoustics, 0 dB refers to the threshold of human hearing, which is the quietest sound that can be detected. It is not an absence of sound, but rather the lowest level of sound that can be perceived.
46.
Wavelength depends on:
Correct Answer(s)
A. Speed of sound
C. Vibration frequency
Explanation
The wavelength of a sound wave is determined by the speed of sound and the vibration frequency. The speed of sound refers to how fast sound waves travel through a medium, such as air or water. The vibration frequency is the number of complete cycles or vibrations that occur per unit of time. Both of these factors affect the distance between two consecutive points of compression or rarefaction in a sound wave, which is known as the wavelength.
47.
Something that is set into forced vibration by another vibration.
Correct Answer(s)
resonator
Explanation
A resonator is an object that is set into forced vibration by another vibration. It is designed to amplify or enhance the vibrations it receives, making it useful in various applications such as musical instruments or electronic circuits. The resonator can resonate at a specific frequency, allowing it to selectively amplify certain vibrations while suppressing others. This makes it an effective tool for controlling and manipulating vibrations in different systems.
48.
Resonators will amplify certain frequencies while dampening others.
Correct Answer
A. True
Explanation
Resonators are devices that vibrate at specific frequencies, and when an external force or sound wave matches the resonant frequency, it amplifies that frequency. This phenomenon is known as resonance. However, resonators also have a damping effect on frequencies that do not match their resonant frequency, reducing their amplitude. Therefore, resonators do amplify certain frequencies while dampening others, making the statement true.
49.
Resonance attenuates frequencies closer to their resonant frequency.
Correct Answer
B. False
Explanation
it attenuates (or dampens) frequencies further from its resonant frequency while amplifying frequencies close to its resonant frequency
50.
The range of frequencies that a resonator will transmit is known as:
Correct Answer
bandwidth
Explanation
The range of frequencies that a resonator will transmit is known as bandwidth. The bandwidth refers to the difference between the highest and lowest frequencies that can pass through a resonator without significant loss or distortion. It determines the ability of the resonator to transmit a wide range of frequencies effectively. A resonator with a larger bandwidth can transmit a wider range of frequencies, while a resonator with a smaller bandwidth is limited to a narrower range.