Question 1

If the intensity of a sound is increased by a factor of 100,how is the decibel level changed? The new decibel level will be:

Accepted Answer

A)  two units greater. 
B)  double the old one. 
C)  ten times greater. 
D)  twenty units greater. 
A)  two units greater. 
B)  double the old one. 
C)  ten times greater. 
D)  twenty units greater.

Question 2

Consider a vibrating string that makes a sound wave that moves through the air.As the guitar string moves up and down,the air molecules that are a certain horizontal distance from the string will move:

Accepted Answer

A)  up and down. 
B)  toward and away from the guitar string. 
C)  back and forth along the direction of the length of the string. 
D)  in circles around the guitar string. 
A)  up and down. 
B)  toward and away from the guitar string. 
C)  back and forth along the direction of the length of the string. 
D)  in circles around the guitar string.

Question 3

A 5-m-long organ pipe is open at one end and closed at the other.Its fundamental tone has wavelength:

Accepted Answer

A)  2.5 m. 
B)  10 m. 
C)  20 m. 
D)  32.5 m. 
E)  ​5 m. 
A)  2.5 m. 
B)  10 m. 
C)  20 m. 
D)  32.5 m. 
E)  ​5 m.

Question 4

When the standing wave pattern in a pipe is NANA,the pipe has which of the following set of properties? (N stands for node,A for antinode. )

Accepted Answer

A)  It is open at both ends. 
B)  It is closed at both ends. 
C)  It is open at one end and closed at the other end. 
D)  Any of the above could be true. 
A)  It is open at both ends. 
B)  It is closed at both ends. 
C)  It is open at one end and closed at the other end. 
D)  Any of the above could be true.

Question 5

The air in a tube open at both ends is sent into its fundamental resonance.One end of the tube is then closed and the air column is again set into its fundamental resonance.The resonant frequency ____ after the end is closed.

Accepted Answer

A)  halves 
B)  stays the same 
C)  doubles 
D)  increases by a factor of 1.4 
A)  halves 
B)  stays the same 
C)  doubles 
D)  increases by a factor of 1.4

Question 6

What is the intensity of sound from a band with a sound level of 123 dB? (I0 = 10−12 W/m2)

Accepted Answer

A)  2.0 W/m2 
B)  1.23 W/m2 
C)  20 W/m2 
D)  12.3 W/m2 
E)  ​123 W/m2 
A)  2.0 W/m2 
B)  1.23 W/m2 
C)  20 W/m2 
D)  12.3 W/m2 
E)  ​123 W/m2

Question 7

Tripling the tension in a guitar string will change its natural frequency by what factor?

Accepted Answer

A)  1.2 
B)  1 
C)  1.7 
D)  3 
E)  ​9 
A)  1.2 
B)  1 
C)  1.7 
D)  3 
E)  ​9

Question 8

Two tuning forks sounding together result in a beat frequency of 4 Hz.If the frequency of one of the forks is 252 Hz,what is the frequency of the other?

Accepted Answer

A)  260 Hz or 244 Hz 
B)  126 Hz 
C)  248 Hz or 256 Hz 
D)  63 Hz 
E)  ​128.0 Hz 
A)  260 Hz or 244 Hz 
B)  126 Hz 
C)  248 Hz or 256 Hz 
D)  63 Hz 
E)  ​128.0 Hz

Question 9

When a sound wave moves through a medium such as air,the motion of the molecules of the medium is in what direction (with respect to the motion of the sound wave)?

Accepted Answer

A)  perpendicular 
B)  parallel 
C)  anti-parallel (in opposite direction) 
D)  Both choices b and c are valid. 
A)  perpendicular 
B)  parallel 
C)  anti-parallel (in opposite direction) 
D)  Both choices b and c are valid.

Question 10

In which part of the ear is the cochlea?

Accepted Answer

A)  outer ear 
B)  middle ear 
C)  inner ear 
D)  ear canal 
A)  outer ear 
B)  middle ear 
C)  inner ear 
D)  ear canal

Question 11

Which of the following ranges corresponds to the longest wavelengths?

Accepted Answer

A)  infrasonic 
B)  audible 
C)  ultrasonic 
D)  all have the same wavelengths 
A)  infrasonic 
B)  audible 
C)  ultrasonic 
D)  all have the same wavelengths

Question 12

You stand by the railroad tracks as a train passes by.You hear a 1,100-Hz frequency when the train approaches,which changes to 870 Hz as it goes away.How fast is the train moving? The speed of sound in air is 340 m/s.

Accepted Answer

A)  26.6 m/s 
B)  33.5 m/s 
C)  37.9 m/s 
D)  39.7 m/s 
E)  ​43.0 m/s 
A)  26.6 m/s 
B)  33.5 m/s 
C)  37.9 m/s 
D)  39.7 m/s 
E)  ​43.0 m/s

Question 13

Of the frequencies listed below,to which one is the human ear most sensitive?

Accepted Answer

A)  33 Hz 
B)  330 Hz 
C)  3 300 Hz 
D)  33 000 Hz 
A)  33 Hz 
B)  330 Hz 
C)  3 300 Hz 
D)  33 000 Hz

Question 14

What is the intensity of a sound with a measured intensity level of 80 dB? (I0 = 10−12 W/m2)

Accepted Answer

A)  1.3 × 10−3 W/m2 
B)  1.0 × 10−4 W/m2 
C)  0.8 × 10−5 W/m2 
D)  10.7 × 10−4 W/m2 
E)  ​8 × 10−4 W/m2 
A)  1.3 × 10−3 W/m2 
B)  1.0 × 10−4 W/m2 
C)  0.8 × 10−5 W/m2 
D)  10.7 × 10−4 W/m2 
E)  ​8 × 10−4 W/m2

Question 15

A train station bell gives off a fundamental tone of 470 Hz as the train approaches the station at a speed of 28 m/s.If the speed of sound in air is 349 m/s,what will be the apparent frequency of the bell to an observer riding the train?

Accepted Answer

A)  432 Hz 
B)  508 Hz 
C)  280 Hz 
D)  498 Hz 
E)  ​349 Hz 
A)  432 Hz 
B)  508 Hz 
C)  280 Hz 
D)  498 Hz 
E)  ​349 Hz

Question 16

What phenomenon is created by two tuning forks,side by side,emitting frequencies,which differ by only a small amount?

Accepted Answer

A)  resonance 
B)  interference 
C)  the Doppler effect 
D)  beats 
A)  resonance 
B)  interference 
C)  the Doppler effect 
D)  beats

Question 17

If the air temperature decreases,how does the resonant frequency in a pipe closed at one end change?

Accepted Answer

A)  It increases. 
B)  It decreases. 
C)  It doesn't change since one end of the pipe is closed. 
D)  It doesn't change because resonance is pressure phenomenon. 
A)  It increases. 
B)  It decreases. 
C)  It doesn't change since one end of the pipe is closed. 
D)  It doesn't change because resonance is pressure phenomenon.

Question 18

A 1.7-m string is held fixed at both ends.When driven by a 165-Hz source,the string vibrates in 2 distinct segments.What is the natural fundamental frequency of the string?

Accepted Answer

A)  83 Hz 
B)  165 Hz 
C)  194 Hz 
D)  291 Hz 
E)  ​140 Hz 
A)  83 Hz 
B)  165 Hz 
C)  194 Hz 
D)  291 Hz 
E)  ​140 Hz

Question 19

If I0 = 10−12 W/m2 is the threshold of hearing,a sound with intensity I1 = 10−11 W/m2 will give a certain decibel level.Suppose a new sound has an intensity I2 = 4I12/I0.What is the new decibel level?

Accepted Answer

A)  2.6 dB 
B)  26 dB 
C)  100 dB 
D)  it will square the decibel level 
E)  ​4 dB 
A)  2.6 dB 
B)  26 dB 
C)  100 dB 
D)  it will square the decibel level 
E)  ​4 dB

Question 20

The number of overtones,and their relative intensities,is associated with what property of the tone generated by a musical instrument?

Accepted Answer

A)  quality 
B)  interference pattern 
C)  range 
D)  attack pattern 
A)  quality 
B)  interference pattern 
C)  range 
D)  attack pattern

Exam 14: Sound

If the intensity of a sound is increased by a factor of 100,how is the decibel level changed? The new decibel level will be:

Consider a vibrating string that makes a sound wave that moves through the air.As the guitar string moves up and down,the air molecules that are a certain horizontal distance from the string will move:

A 5-m-long organ pipe is open at one end and closed at the other.Its fundamental tone has wavelength:

When the standing wave pattern in a pipe is NANA,the pipe has which of the following set of properties? (N stands for node,A for antinode. )

The air in a tube open at both ends is sent into its fundamental resonance.One end of the tube is then closed and the air column is again set into its fundamental resonance.The resonant frequency ____ after the end is closed.

What is the intensity of sound from a band with a sound level of 123 dB? (I0 = 10−12 W/m2)

Tripling the tension in a guitar string will change its natural frequency by what factor?

Two tuning forks sounding together result in a beat frequency of 4 Hz.If the frequency of one of the forks is 252 Hz,what is the frequency of the other?

When a sound wave moves through a medium such as air,the motion of the molecules of the medium is in what direction (with respect to the motion of the sound wave)?

In which part of the ear is the cochlea?

Which of the following ranges corresponds to the longest wavelengths?

You stand by the railroad tracks as a train passes by.You hear a 1,100-Hz frequency when the train approaches,which changes to 870 Hz as it goes away.How fast is the train moving? The speed of sound in air is 340 m/s.

Of the frequencies listed below,to which one is the human ear most sensitive?

What is the intensity of a sound with a measured intensity level of 80 dB? (I0 = 10−12 W/m2)

A train station bell gives off a fundamental tone of 470 Hz as the train approaches the station at a speed of 28 m/s.If the speed of sound in air is 349 m/s,what will be the apparent frequency of the bell to an observer riding the train?

What phenomenon is created by two tuning forks,side by side,emitting frequencies,which differ by only a small amount?

If the air temperature decreases,how does the resonant frequency in a pipe closed at one end change?

A 1.7-m string is held fixed at both ends.When driven by a 165-Hz source,the string vibrates in 2 distinct segments.What is the natural fundamental frequency of the string?

If I0 = 10−12 W/m2 is the threshold of hearing,a sound with intensity I1 = 10−11 W/m2 will give a certain decibel level.Suppose a new sound has an intensity I2 = 4I12/I0.What is the new decibel level?

The number of overtones,and their relative intensities,is associated with what property of the tone generated by a musical instrument?

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound: Part A

Electric Forces and Electric Fields

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Magnetism Magnets: Part A

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

What is the intensity of sound from a band with a sound level of 123 dB? (I₀ = 10−¹² W/m²)

What is the intensity of a sound with a measured intensity level of 80 dB? (I₀ = 10−¹² W/m²)

If I₀ = 10−¹² W/m² is the threshold of hearing,a sound with intensity I₁ = 10−¹¹ W/m² will give a certain decibel level.Suppose a new sound has an intensity I₂ = 4I₁²/I₀.What is the new decibel level?