Chapter 20
Sound
The sound waves that most humans
cannot hear are
a.
b.
c.
d.
infrasonic.
ultrasonic.
Both of these.
None of the above, for young people can hear
both.
The sound waves that most humans
cannot hear are
a.
b.
c.
d.
infrasonic.
ultrasonic.
Both of these.
None of the above, for young people can hear
both.
Sound travels in air by a series of
a.
b.
c.
d.
compressions.
rarefactions.
Both of these.
None of these.
Sound travels in air by a series of
a.
b.
c.
d.
compressions.
rarefactions.
Both of these.
None of these.
The vibrations set up in a radio
loudspeaker have the same frequencies
as the vibrations
a.
b.
c.
d.
in the electric signal feeding the loudspeaker.
that produce the sound you hear.
Both of these.
None of these.
The vibrations set up in a radio
loudspeaker have the same frequencies
as the vibrations
a.
b.
c.
d.
in the electric signal feeding the loudspeaker.
that produce the sound you hear.
Both of these.
None of these.
Sound travels in
a.
b.
c.
d.
solids.
liquids.
gases.
All of these.
Sound travels in
a.
b.
c.
d.
solids.
liquids.
gases.
All of these.
In which of these materials does
sound travel fastest?
a.
b.
c.
d.
Air
Water
Steel
All the same at the same temperature
In which of these materials does
sound travel fastest?
a.
b.
c.
d.
Air
Water
Steel
All the same at the same temperature
The speed of sound varies with
a.
b.
c.
d.
amplitude.
frequency.
temperature.
All of these.
The speed of sound varies with
a.
b.
c.
d.
amplitude.
frequency.
temperature.
All of these.
Explanation: Although loudness varies with amplitude, and pitch
varies with frequency, speed is not influenced by amplitude
nor frequency. A listener in the back row at a concert would
find music confusing if sound of different frequencies reached
the ear at different times.
The loudness of a sound is most
closely related to its
a.
b.
c.
d.
frequency.
period.
wavelength.
amplitude.
The loudness of a sound is most
closely related to its
a.
b.
c.
d.
frequency.
period.
wavelength.
amplitude.
Sound made to undergo reverberation
is sound that is
a.
b.
c.
d.
sympathetically vibrating.
varying in tone.
multiply reflected.
refracted.
Sound made to undergo reverberation
is sound that is
a.
b.
c.
d.
sympathetically vibrating.
varying in tone.
multiply reflected.
refracted.
When sound undergoes refraction, it
undergoes a change in
a.
b.
c.
d.
frequency.
wavelength.
speed.
intensity.
When sound undergoes refraction, it
undergoes a change in
a.
b.
c.
d.
frequency.
wavelength.
speed.
intensity.
Sound can NOT be
a.
b.
c.
d.
reflected.
absorbed.
diminished by interference.
None of these.
Sound can NOT be
a.
b.
c.
d.
reflected.
absorbed.
diminished by interference.
None of these.
Comment: Sound, like any wave, can undergo all of these!
Sensing an invisible object by way of
ultrasound is used by
a.
b.
c.
d.
bats.
dolphins
medical doctors.
All of these.
Sensing an invisible object by way of
ultrasound is used by
a.
b.
c.
d.
bats.
dolphins
medical doctors.
All of these.
Sound normally travels farther in air
when the sound is
a.
b.
c.
d.
low frequency.
high frequency.
resonant.
low in energy.
Sound normally travels farther in air
when the sound is
a.
b.
c.
d.
low frequency.
high frequency.
resonant.
low in energy.
Explanation: Hence the low tone of fog horns.
A factory floor vibrates, and as a result
you vibrate when standing on the floor.
This is
a.
b.
c.
d.
forced vibration.
resonance.
refraction.
diffraction.
A factory floor vibrates, and as a result
you vibrate when standing on the floor.
This is
a.
b.
c.
d.
forced vibration.
resonance.
refraction.
diffraction.
When you tap various objects, they
produce characteristic sounds that are
related to
a.
b.
c.
d.
wavelength.
amplitude.
period.
natural frequency.
When you tap various objects, they
produce characteristic sounds that are
related to
a.
b.
c.
d.
wavelength.
amplitude.
period.
natural frequency.
When the surface of a guitar is made
to vibrate, we say it undergoes
a.
b.
c.
d.
forced vibration.
resonance.
refraction.
amplitude enhancement.
When the surface of a guitar is made
to vibrate, we say it undergoes
a.
b.
c.
d.
forced vibration.
resonance.
refraction.
amplitude enhancement.
Comment: The sound may be enhanced, but it is the surface
of the guitar that undergoes forced vibration.
When an object is set vibrating by a
wave having a frequency that matches
the natural frequency of the object, what
occurs is
a.
b.
c.
d.
forced vibration.
resonance.
refraction.
amplitude enhancement.
When an object is set vibrating by a
wave having a frequency that matches
the natural frequency of the object, what
occurs is
a.
b.
c.
d.
forced vibration.
resonance.
refraction.
amplitude enhancement.
Comment: Resonance, rather than amplitude enhancement,
is the better answer.
Noise-canceling devices such as
jackhammer earphones make use of
sound
a.
b.
c.
d.
destruction.
interference.
resonance.
amplification.
Noise-canceling devices such as
jackhammer earphones make use of
sound
a.
b.
c.
d.
destruction.
interference.
resonance.
amplification.
The phenomenon of beats is the
result of sound
a.
b.
c.
d.
destruction.
interference.
resonance.
amplification.
The phenomenon of beats is the
result of sound
a.
b.
c.
d.
destruction.
interference.
resonance.
amplification.
When a 134-Hz tuning fork and a
144-Hz tuning fork are struck, the
beat frequency is
a.
b.
c.
d.
2 Hz.
6 Hz.
8 Hz.
more than 8 Hz.
When a 134-Hz tuning fork and a
144-Hz tuning fork are struck, the
beat frequency is
a.
b.
c.
d.
2 Hz.
6 Hz.
8 Hz.
more than 8 Hz.
Explanation: The beat frequency is the difference between
the two, 10 Hz (which is more than 8 Hz).
When your radio set is tuned to an
incoming radio signal, what occurs?
a.
b.
c.
d.
Forced vibration
Resonance
Refraction
Diffraction
When your radio set is tuned to an
incoming radio signal, what occurs?
a.
b.
c.
d.
Forced vibration
Resonance
Refraction
Diffraction