PHY 112 Chpt 17 Nature Production Qnd Propagation Of Sound

Question 1

1. Light is a form of energy that travels through a medium by: a) Conduction b) Convection c) Radiation d) All of the above

Answer 1

Answer: d) All of the aboveExplanation: light can travel through a medium by conduction convection and radiation. Conduction is the transfer of heat through direct contact. Convection involves the movement of fluids (liquids or gases). Radiation involves the transfer of energy through electromagnetic waves.

Question 2

2. The speed of sound in air is approximately: a) 343 m/s b) 300 m/s c) 1000 m/s d) 1500 m/s

Answer 2

Answer: a) 343 m/sExplanation: The speed of sound in air at room temperature is approximately 343 m/s. This speed can vary slightly depending on factors like temperature and humidity.

Question 3

3. Which of the following is NOT a characteristic of sound waves? a) They are longitudinal waves b) They require a medium to travel c) They can travel in a vacuum d) They can be reflected and refracted

Answer 3

Answer: c) They can travel in a vacuumExplanation: Sound waves are mechanical waves and require a medium (like air water or solids) to propagate. They cannot travel through a vacuum.

Question 4

4. The regions of high pressure in a sound wave are called: a) Compressions b) Rarefactions c) Nodes d) Antinodes

Answer 4

Answer: a) CompressionsExplanation: Compressions are regions of high pressure in a sound wave where the particles of the medium are close together. Rarefactions are regions of low pressure where the particles are farther apart.

Question 5

5. The human ear can detect sound waves with frequencies between: a) 20 Hz to 20 000 Hz b) 10 Hz to 10 000 Hz c) 1 Hz to 1000 Hz d) 100 Hz to 100000 Hz

Answer 5

Answer: a) 20 Hz to 20 000 HzExplanation: The human ear is sensitive to sound waves with frequencies between 20 Hz and 20 000 Hz. This range is known as the audible frequency range.

Question 6

6. The intensity of a sound wave is proportional to the: a) Amplitude of the wave b) Frequency of the wave c) Speed of the wave d) Wavelength of the wave

Answer 6

Answer: a) Amplitude of the waveExplanation: The intensity of a sound wave is a measure of the power it carries per unit area. It is directly proportional to the square of the amplitude of the wave.

Question 7

7. The unit of loudness is: a) Decibel (dB) b) Hertz (Hz) c) Phon d) Watt (W)

Answer 7

Answer: c) PhonExplanation: The Phon is the unit of loudness which is a subjective measure of how loud a sound is perceived. Decibels (dB) are used to measure sound intensity.

Question 8

8. The phenomenon of sound waves bouncing off a surface is called: a) Diffraction b) Refraction c) Reflection d) Interference

Answer 8

Answer: c) ReflectionExplanation: Reflection occurs when sound waves bounce off a surface. Diffraction involves the bending of waves around corners. Refraction involves the bending of waves as they pass from one medium to another. Interference occurs when waves overlap and either reinforce or cancel each other out.

Question 9

9. The time taken for a sound wave to travel from a source to a listener and back is called: a) Echo time b) Reverberation time c) Resonance time d) Beat frequency

Answer 9

Answer: a) Echo timeExplanation: The time taken for a sound wave to travel from a source to a listener and back is called the echo time. Reverberation time refers to the time it takes for a sound to decay in an enclosed space. Resonance time refers to the time it takes for an object to vibrate at its natural frequency. Beat frequency refers to the difference in frequency between two sound waves.

Question 10

10. The fundamental frequency of a vibrating string is directly proportional to: a) The length of the string b) The tension in the string c) The mass per unit length of the string d) All of the above

Answer 10

Answer: d) All of the aboveExplanation: The fundamental frequency of a vibrating string is directly proportional to the square root of the tension in the string inversely proportional to the length of the string and inversely proportional to the square root of the mass per unit length of the string.

Question 11

11. When a vibrating object forces another object to vibrate at its natural frequency it is called: a) Resonance b) Interference c) Diffraction d) Refraction

Answer 11

Answer: a) ResonanceExplanation: Resonance occurs when an object is forced to vibrate at its natural frequency. This results in a significant increase in the amplitude of vibration producing a louder sound.

Question 12

12. The phenomenon of sound waves spreading out as they pass through an opening is called: a) Diffraction b) Refraction c) Reflection d) Interference

Answer 12

Answer: a) DiffractionExplanation: Diffraction is the spreading of waves as they pass through an opening or around obstacles.

Question 13

13. The unit of power is: a) Hertz (Hz) b) Watt (W) c) Decibel (dB) d) Phon

Answer 13

Answer: b) Watt (W)Explanation: The watt (W) is the unit of power which is the rate at which energy is transferred.

Question 14

14. The quality of a sound that allows us to distinguish between a flute and a guitar is called: a) Pitch b) Loudness c) Timbre d) Intensity

Answer 14

Answer: c) TimbreExplanation: Timbre is the quality of a sound that allows us to distinguish between different musical instruments or voices even if they are playing the same note at the same loudness. It’s the unique character or “color” of the sound.

Question 15

15. The frequency of a sound wave determines its: a) Loudness b) Pitch c) Timbre d) Intensity

Answer 15

Answer: b) PitchExplanation: The frequency of a sound wave determines its pitch. Higher frequencies correspond to higher pitches and lower frequencies correspond to lower pitches.

Question 16

16. The phenomenon of the superposition of waves resulting in increased or decreased amplitude is called: a) Diffraction b) Interference c) Refraction d) Resonance

Answer 16

Answer: b) InterferenceExplanation: Interference is the phenomenon of the superposition of waves resulting in increased or decreased amplitude. Constructive interference occurs when the waves are in phase and add together. Destructive interference occurs when the waves are out of phase and cancel each other out.

Question 17

17. The speed of sound in a medium depends on: a) The temperature of the medium b) The density of the medium c) The elasticity of the medium d) All of the above

Answer 17

Answer: d) All of the aboveExplanation: The speed of sound in a medium depends on the temperature density and elasticity of the medium. Higher temperatures lower densities and higher elasticity generally result in faster sound speeds.

Question 18

18. The phenomenon of sound waves bending as they pass from one medium to another is called: a) Diffraction b) Refraction c) Reflection d) Interference

Answer 18

Answer: b) RefractionExplanation: Refraction is the bending of waves as they pass from one medium to another. This occurs because the speed of sound changes as it moves from one medium to another.

Question 19

19. The human ear is most sensitive to sound waves in the frequency range of: a) 1000-5000 Hz b) 100-1000 Hz c) 5000-10000 Hz d) 10000-20000 Hz

Answer 19

Answer: a) 1000-5000 HzExplanation: The human ear is most sensitive to sound waves in the frequency range of 1000-5000 Hz. This is the frequency range that includes most speech sounds.

Question 20

20. The phenomenon of sound waves being trapped in an enclosed space and reflecting multiple times is called: a) Resonance b) Reverberation c) Echo d) Interference

Answer 20

Answer: b) ReverberationExplanation: Reverberation is the persistence of sound in an enclosed space after the sound source has stopped. It is caused by multiple reflections of sound waves off the walls ceilings and other surfaces within the enclosure.

Question 21

21. The fundamental frequency of an open air column is: a) Directly proportional to its length b) Inversely proportional to its length c) Independent of its length d) Directly proportional to its diameter

Answer 21

Answer: b) Inversely proportional to its lengthExplanation: The fundamental frequency of an open air column is inversely proportional to its length. This means that a longer air column will produce a lower fundamental frequency.

Question 22

22. The fundamental frequency of a closed air column is: a) Directly proportional to its lengthb) Inversely proportional to its lengthc) Independent of its lengthd) Directly proportional to its diameter

Answer 22

Answer: b) Inversely proportional to its lengthExplanation: The fundamental frequency of a closed air column is inversely proportional to its length. This means that a longer closed air column will produce a lower fundamental frequency.

Question 23

23. The phenomenon of a vibrating string causing a nearby string to vibrate at its own natural frequency is an example of:a) Resonanceb) Interferencec) Diffractiond) Refraction

Answer 23

Answer: a) ResonanceExplanation: This is a classic example of resonance. The vibrating string forces the nearby string to vibrate at its natural frequency

Question 24

24. A sonometer is used to study the relationship between: a) The frequency of a vibrating string and its lengthb) The frequency of a vibrating string and its tensionc) The frequency of a vibrating string and its mass per unit lengthd) All of the above

Answer 24

Answer: d) All of the aboveExplanation: A sonometer is a device used to study the relationship between the frequency of a vibrating string

Question 25

25. The phenomenon of sound waves bending around corners is called: a) Diffractionb) Refractionc) Reflectiond) Interference

Answer 25

Answer: a) DiffractionExplanation: Diffraction is the bending of waves around corners or obstacles. It’s a property of all waves

Question 26

26. What is the relationship between the frequency and wavelength of a sound wave? a) Frequency and wavelength are directly proportionalb) Frequency and wavelength are inversely proportionalc) Frequency and wavelength are independent of each otherd) The relationship depends on the medium

Answer 26

Answer: b) Frequency and wavelength are inversely proportionalExplanation: The speed of a wave (v) is related to its frequency (f) and wavelength (λ) by the equation: v = fλ. Since the speed of sound in a given medium is constant

Question 27

27. What is the difference between a compression and a rarefaction in a sound wave? a) A compression is a region of high pressure while a rarefaction is a region of low pressureb) A compression is a region of low pressure while a rarefaction is a region of high pressurec) A compression is a region where the particles are close together while a rarefaction is a region where the particles are far apartd) A compression is a region where the particles are far apart while a rarefaction is a region where the particles are close together

Answer 27

Answer: a) A compression is a region of high pressure while a rarefaction is a region of low pressureLANDc) A compression is a region where the particles are close together while a rarefaction is a region where the particles are far apartExplanation: These two answers are both correct as they describe the same phenomenon in different ways. Compressions are regions of high pressure where the particles of the medium are crowded together. Rarefactions are regions of low pressure where the particles are farther apart.

Question 28

28. Explain the concept of intensity as it relates to sound.

Answer 28

Intensity of sound is a measure of the power carried by sound waves per unit area. It is directly proportional to the square of the amplitude of the sound wave. The unit of intensity is the watt per square meter (W/m²). Higher intensity sound waves correspond to louder sounds.

Question 29

29. How do sound waves interact with different materials?

Answer 29

Sound waves can be reflected refracted absorbed or transmitted through materials depending on the properties of the material. Reflection occurs when sound waves bounce back from a surface. Refraction occurs when sound waves bend as they pass from one medium to another. Absorption occurs when sound waves lose energy as they pass through a material. Transmission occurs when sound waves pass through a material relatively unchanged.

Question 30

30. What is the difference between sound waves and light waves

Answer 30

Sound waves are mechanical waves that require a medium to travel while light waves are electromagnetic waves that can travel through a vacuum. Sound waves are longitudinal meaning the particles of the medium vibrate parallel to the direction of wave propagation while light waves are transverse meaning the particles of the medium vibrate perpendicular to the direction of wave propagation.

Question 31

31. Explain the concept of timbre and give an example of how timbre can be used to distinguish between musical instruments.

Answer 31

Timbre refers to the unique quality or “color” of a sound that allows us to distinguish between different sounds

Question 32

32. What does the term ‘fundamental frequency’ mean in the context of a vibrating string?a) The frequency at which the string vibrates with maximum amplitudeb) The lowest frequency at which the string vibrates naturallyc) The frequency at which the string vibrates with minimum amplituded) The highest frequency at which the string vibrates naturally

Answer 32

Answer: b) The lowest frequency at which the string vibrates naturallyExplanation: The fundamental frequency is the lowest natural frequency of a vibrating string. It produces the base pitch of the sound and is associated with the simplest mode of vibration

Question 33

33. In terms of frequency and wavelength which of the following waves would you expect to have the highest pitch?a) Long wavelength

Answer 33

low frequencyb) Long wavelength

Question 34

34. The speed of sound is fastest in which of the following materials?a) Airb) Waterc) Woodd) Steel

Answer 34

Answer: d) SteelExplanation: Sound travels fastest in dense more elastic materials. Steel being a solid and highly elastic material allows sound waves to travel more quickly compared to air. water and wood.

Question 35

35. Which of the following factors does not affect the speed of sound in air a) Temperatureb) Pressurec) Humidityd) The frequency of the sound

Answer 35

Answer: d) The frequency of the soundExplanation: The speed of sound in air is primarily affected by factors such as temperature pressure and humidity but it is independent of the sound wave’s frequency.