Sound Waves: Speed, Intensity, and Doppler Effect

Question 1

The formula for the speed of sound in air is:

Accepted Answer

v = λf

Answer

v = fλ

Answer

v = f/λ

Answer

v = λ/f

Question 2

The SI unit of sound intensity is the:

Accepted Answer

Watt per square meter (W/m²)

Answer

Newton per square meter (N/m²)

Answer

Pascal per square meter (Pa/m²)

Answer

Joule per cubic meter (J/m³)

Question 3

Which of the following factors does not affect the speed of sound in a gas?

Accepted Answer

Volume

Answer

Temperature

Answer

Pressure

Answer

Density

Question 4

The relationship between sound intensity and distance from the source is described by the inverse square law. This means that the intensity of sound:

Accepted Answer

Is inversely proportional to the square of distance

Answer

Is proportional to distance

Answer

Is inversely proportional to distance

Answer

Is independent of distance

Question 5

Ultrasonic waves are characterized by:

Accepted Answer

Frequencies above the range of human hearing

Answer

Wavelengths longer than the size of a human

Answer

Amplitudes too low to be detected by humans

Answer

Speeds of propagation slower than the speed of light

Question 6

The effect of increasing temperature on the speed of sound in a gas is that the speed:

Accepted Answer

Increases

Answer

Decreases

Answer

Is not affected

Answer

Increases then decreases

Question 7

Which of the following is not a property of sound waves?

Accepted Answer

Can be polarized

Answer

Can be reflected

Answer

Can be refracted

Answer

Can be diffracted

Question 8

A characteristic property of a sound wave is:

Accepted Answer

Both Speed and Intensity

Answer

Speed

Answer

Intensity

Question 9

The speed of sound in air at room temperature is approximately:

Accepted Answer

343 meters per second (m/s)

Answer

1235 kilometers per hour (km/h)

Answer

299,792,458 meters per second (m/s)

Answer

186,000 miles per second (mi/s)

Question 10

The intensity of a sound wave is primarily influenced by its:

Accepted Answer

Amplitude

Answer

Frequency

Answer

Distance from the source

Answer

Sound velocity

Question 11

The Doppler effect refers to the:

Accepted Answer

Change in sound frequency due to relative motion between source and observer

Answer

Reflection of sound waves from a surface

Answer

Absorption of sound waves by a material

Answer

Refraction of sound waves at an interface

Question 12

For a sound wave with a frequency of 500 Hertz (Hz) and a speed of 343 meters per second (m/s), its wavelength is:

Accepted Answer

0.686 meters (m)

Answer

1470 Hertz (Hz)

Answer

0.0029 meters (m)

Answer

343 meters (m)

Question 13

Which of the following materials is considered a good sound insulator?

Accepted Answer

Styrofoam

Answer

Metal

Answer

Wood

Answer

Concrete

Question 14

The standard unit for measuring sound intensity is the:

Accepted Answer

Watts per square meter (W/m²)

Answer

Decibels (dB)

Answer

Hertz (Hz)

Answer

Meters per second (m/s)

Question 15

A sonar system operates on the principle of:

Accepted Answer

Using sound waves to determine the distance to objects

Answer

Using light waves to measure underwater depths

Answer

Using electromagnetic waves to locate objects

Answer

Using radar waves to detect aircraft

Question 16

In air at room temperature (approximately 20 °C), the speed of sound is:

Accepted Answer

343 m/s

Answer

123 m/s

Answer

680 m/s

Answer

981 m/s

Question 17

Define the Doppler effect.

Accepted Answer

The shift in frequency of sound waves due to relative motion between source and observer

Answer

The reflection of sound waves off surfaces

Answer

The interference of sound waves producing beats

Answer

The absorption of sound waves by materials

Question 18

Which material is most effective at absorbing sound waves?

Accepted Answer

Acoustic foam

Answer

Wood

Answer

Concrete

Answer

Metal

Question 19

A sound wave has an intensity of 10^-12 W/m². Determine its sound intensity level in decibels.

Accepted Answer

30 dB

Answer

120 dB

Answer

60 dB

Answer

0 dB

Question 20

What is the primary function of soundproofing materials?

Accepted Answer

Absorbing sound waves

Answer

Reflecting sound waves

Answer

Amplifying sound waves

Answer

Dispersing sound waves

Question 21

Which of the following factors does NOT affect the speed of sound in a medium?

Accepted Answer

Frequency of the sound wave

Answer

Density of the medium

Answer

Temperature of the medium

Answer

Elasticity of the medium

Question 22

A sound wave with higher intensity will have:

Accepted Answer

Greater amplitude

Answer

Higher frequency

Answer

Lower speed

Answer

Longer wavelength

Question 23

Define the Doppler effect.

Accepted Answer

Frequency change in sound waves due to object movement

Answer

Amplitude change in sound waves due to object movement

Answer

Speed change in sound waves due to object movement

Answer

Wavelength change in sound waves due to object movement

Question 24

What is the unit of sound intensity in the International System of Units (SI)?

Accepted Answer

Watts per square meter

Answer

Decibels

Answer

Candelas per square meter

Answer

Newtons per square meter

Question 25

Which of the following is NOT a property of sound waves?

Accepted Answer

Transverse

Answer

Longitudinal

Answer

Mechanical

Answer

Compressional

Question 26

Which of the following is NOT a fundamental property of sound waves?

Accepted Answer

Polarization

Answer

Frequency

Answer

Amplitude

Answer

Wavelength

Question 27

The speed of sound in air at room temperature is approximately:

Accepted Answer

343 m/s

Answer

550 m/s

Answer

1,500 m/s

Answer

2,997 m/s

Question 28

The Doppler effect is primarily caused by:

Accepted Answer

The relative motion between a sound source and an observer

Answer

Variations in the speed of sound

Answer

Changes in the wavelength of sound

Answer

The presence of obstacles in the sound path

Question 29

Which of the following materials has the highest sound wave absorption capacity?

Accepted Answer

Fiberglass

Answer

Metal

Answer

Wood

Answer

Water

Question 30

The standard unit of measurement for sound intensity is:

Accepted Answer

Watts per square meter

Answer

Decibels

Answer

Hertz

Answer

Pascals

Question 31

The speed of sound in air at room temperature (20 degrees Celsius) is approximately:

Accepted Answer

343 m/s

Answer

331 m/s

Answer

355 m/s

Answer

367 m/s

Question 32

Which of the following factors does NOT influence the speed of sound in a medium?

Accepted Answer

Frequency

Answer

Temperature

Answer

Pressure

Answer

Density

Question 33

A sound wave in air has a frequency of 500 Hz and a wavelength of 0.686 m. Determine the speed of sound in air.

Accepted Answer

343 m/s

Answer

330 m/s

Answer

356 m/s

Answer

369 m/s

Question 34

Identify the type of sound wave that is NOT possible:

Accepted Answer

Transverse

Answer

Longitudinal

Answer

Plane

Answer

Spherical

Question 35

Which material is most likely to exhibit a high acoustic impedance?

Accepted Answer

Concrete

Answer

Air

Answer

Water

Answer

Foam rubber

Question 36

What is the primary function of a resonant frequency in a sound system?

Accepted Answer

To enhance specific frequencies

Answer

To eliminate unwanted noise

Answer

To prevent acoustic feedback

Answer

To improve overall sound quality

Question 37

Which of the following is NOT an essential property of sound waves?

Accepted Answer

Electric field

Answer

Amplitude

Answer

Wavelength

Answer

Frequency

Question 38

At room temperature, the speed of sound in air is approximately:

Accepted Answer

343 m/s

Answer

510 m/s

Answer

171 m/s

Answer

273 m/s

Question 39

Which of the following directly affects the intensity of a sound wave?

Accepted Answer

Amplitude

Answer

Phase

Answer

Wavelength

Answer

Frequency

Question 40

The Doppler effect occurs when:

Accepted Answer

The source or observer moves relative to the medium

Answer

The sound wave is absorbed by an object

Answer

The sound wave is refracted through a different medium

Answer

The sound wave is reflected off a surface

Question 41

Which of the following materials would allow sound waves to travel through it most quickly?

Accepted Answer

Steel

Answer

Wood

Answer

Air

Answer

Water

Question 42

Calculate the wavelength of a sound wave with a frequency of 500 Hz and a speed of 343 m/s.

Accepted Answer

0.686 m

Answer

0.343 m

Answer

1.372 m

Answer

0.500 m

Question 43

What is the standard unit of measurement for sound intensity?

Accepted Answer

Watts per square meter (W/m²)

Answer

Hertz (Hz)

Answer

Decibels (dB)

Question 44

Which of the following properties of a sound wave primarily determines its loudness?

Accepted Answer

Amplitude

Answer

Speed

Answer

Wavelength

Answer

Frequency

Question 45

Define the Doppler effect in the context of sound waves.

Accepted Answer

The change in frequency or wavelength of a sound wave due to the relative motion between the sound source and the observer or detector.

Answer

The reflection of sound waves at a boundary

Answer

The absorption of sound energy by a medium

Question 46

Which of the following is a practical application of the Doppler effect for sound waves?

Accepted Answer

Measuring the speed of moving objects

Answer

Enhancing the sound quality of audio recordings

Answer

Creating special sound effects

Question 47

What is the approximate speed of sound in air at room temperature (20°C)?

Accepted Answer

343 m/s

Answer

1000 m/s

Answer

299,792,458 m/s

Answer

170 m/s

Question 48

Which of the following materials generally has the highest speed of sound?

Accepted Answer

Steel

Answer

Water

Answer

Rubber

Answer

Air

Question 49

What is a standing wave?

Accepted Answer

A wave that is confined to a particular region and exhibits fixed points of zero displacement

Answer

A wave that travels in only one direction

Answer

A wave with constant amplitude

Question 50

Define the resonance frequency of a vibrating string.

Accepted Answer

The frequency at which the string naturally vibrates with the greatest amplitude

Answer

The frequency at which the string is initially plucked or excited

Answer

The frequency at which the string produces the loudest sound