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Question 1:

Which property of sound refers to the amount of energy carried by a sound wave per unit of area?

A) Wavelength
B) Frequency
C) Amplitude
D) Pitch

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Explanation: The correct answer is C) Amplitude. Sound intensity refers to the amount of energy carried by a sound wave per unit of area. It is directly related to the amplitude of the sound wave, with greater amplitudes corresponding to higher sound intensities. Sound intensity is typically measured in units like watts per square meter (W/m²) or decibels (dB).

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Question 2:

What is the threshold of hearing on the decibel scale?

A) 0 dB
B) 10 dB
C) 20 dB
D) 30 dB

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Explanation: The correct answer is A) 0 dB. The threshold of hearing, or the lowest sound level that can be detected by the average human ear, is defined as 0 decibels (dB). This level corresponds to the faintest sound that can be heard under ideal conditions in a quiet environment.

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Question 3:

How does the sound intensity level change when the sound intensity doubles?

A) The sound intensity level decreases by 3 dB
B) The sound intensity level increases by 3 dB
C) The sound intensity level decreases by 6 dB
D) The sound intensity level remains the same

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Explanation: The correct answer is B) The sound intensity level increases by 3 dB. The sound intensity level is measured on a logarithmic scale known as the decibel (dB) scale. When the sound intensity doubles, the sound intensity level increases by approximately 3 decibels. This is because the decibel scale is based on a logarithmic relationship that accounts for the human perception of sound.

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Question 4:

What is the sound intensity level of a sound with an intensity of 10^(-12) watts per square meter (W/m²)?

A) 0 dB
B) 10 dB
C) 20 dB
D) 30 dB

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Explanation: The correct answer is C) 20 dB. The sound intensity level can be calculated using the formula: sound intensity level (in dB) = 10 * log10(I/I0), where I is the sound intensity and I0 is the reference intensity of 10^(-12) W/m². Plugging in the values, we get: sound intensity level = 10 * log10(10^(-12)/10^(-12)) = 20 dB.

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Question 5:

What is the approximate sound intensity level of a sound with a power of 1 milliwatt (mW)?

A) 0 dB
B) 30 dB
C) 60 dB
D) 90 dB

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Explanation: The correct answer is C) 60 dB. The sound intensity level can be calculated using the formula: sound intensity level (in dB) = 10 * log10(P/P0), where P is the sound power and P0 is the reference power of 1 picowatt (10^(-12) W). Converting 1 milliwatt to watts (1 mW= 0.001 W), we get: sound intensity level = 10 * log10(0.001/10^(-12)) = 60 dB.