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1 | |
Sound waves are longitudinal waves that require a medium for transmission. |
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| | A) | True |
| | B) | False |
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2 | |
If a tree falls in a forest, there is no sound unless an ear can pick up the vibrations. |
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| | A) | True |
| | B) | False |
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3 | |
Sound waves travel faster in air than in metals because the air is less dense. |
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| | A) | True |
| | B) | False |
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4 | |
The speed of sound is increased significantly with rising temperatures. |
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| | A) | True |
| | B) | False |
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5 | |
The quality of different sounds is demonstrated by the difference in tones when a C note is sounded on a flute, a violin, and a trumpet. |
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| | A) | True |
| | B) | False |
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6 | |
A sound of intensity level 40 dB is twice as intense as a sound of 20 dB. |
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| | A) | True |
| | B) | False |
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7 | |
Sound that fluctuates in intensity because of the simultaneous output of two sources is a consequence primarily of the Doppler effect. |
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| | A) | True |
| | B) | False |
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8 | |
In applying Doppler’s equation, speeds are reckoned as positive for speeds of approach and negative for speeds of recession. |
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| | A) | True |
| | B) | False |
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9 | |
Opening the end of a closed pipe will double the frequency produced. |
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| | A) | True |
| | B) | False |
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10 | |
The speed of sound in gases is larger for the gases with higher molecular masses. |
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| | A) | True |
| | B) | False |
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11 | |
The speed of sound is greatest when the medium is |
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| | A) | a vacuum |
| | B) | air |
| | C) | water |
| | D) | metal |
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12 | |
Which of the following is a sensory effect rather than a measurable physical quantity? |
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| | A) | Frequency |
| | B) | Quality |
| | C) | Intensity |
| | D) | Waveform |
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13 | |
For a closed pipe, the second overtone is the |
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| | A) | second harmonic |
| | B) | third harmonic |
| | C) | fourth harmonic |
| | D) | fifth harmonic |
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14 | |
The physical property that is most responsible for resonance is |
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| | A) | waveform |
| | B) | frequency |
| | C) | quality |
| | D) | intensity |
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15 | |
Which of the following sounds is loudest? |
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| | A) | 40 dB |
| | B) | 10-5M
µW/cm² |
| | C) | 10-10 W/m² |
| | D) | 3 B |
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16 | |
The speed of sound in air at 0°C is 331 m/s. Its speed at 30°C is approximately |
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| | A) | 331 m/s |
| | B) | 343 m/s |
| | C) | 349 m/s |
| | D) | 350 m/s |
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17 | |
The fundamental frequency for a 20-cm closed pipe when the speed of sound is 340 m/s is |
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| | A) | 4.25 Hz |
| | B) | 8.25 Hz |
| | C) | 425 Hz |
| | D) | 825 Hz |
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18 | |
The intensity level in decibels of a sound whose intensity is 2 X -10-6µW/cm² is approximately |
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| | A) | 27 dB |
| | B) | 43 dB |
| | C) | 50 dB |
| | D) | 103 dB |
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19 | |
A car horn emits sound at a frequency of 200 Hz. The pitch heard when the car is moving at 31 m/s toward an observer in air at 0°C is approximately |
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| | A) | 221 Hz |
| | B) | 219 Hz |
| | C) | 181 Hz |
| | D) | 183 Hz |
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20 | |
Two tuning forks of 340 and 343 Hz are sounded together. The resulting beats per second will be |
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| | A) | 1 |
| | B) | 2 |
| | C) | 3 |
| | D) | 4 |
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21 | |
The closed end of a pipe must be a displacement ; the open end must be a displacement . |
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22 | |
The velocity of sound waves in a liquid is equal to the square root of the ratio of its to its . |
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23 | |
The three physical properties of sound that correspond to loudness, pitch, and quality are , , and , respectively. |
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24 | |
The represents the standard zero of sound intensity. Its value is W/cm². |
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25 | |
Sound waves having frequencies below the range of audible sound are termed ; sounds having frequencies above this range are termed . |
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26 | |
For a closed pipe, only the harmonics are possible. Thus, the seventh harmonic will be the overtone. |
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27 | |
The power transmitted by a sound wave through a unit of area is a measure of . |
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28 | |
The refers to the apparent change in frequency of a source of sound when there is relative motion between the source and the observer. The pitch heard by an observer is when a sound approaches her or him and when the sound leaves. |
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29 | |
Beats are the product of alternating and interference of sound waves of slightly different frequency. |
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30 | |
When the intensity I1 of one sound is 10 times as great as the intensity I2 of another, the difference in intensity levels is said to be 1 . |
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