Chapter 11 Sound Questions-03
Questions
1. What are wavelength, frequency, time period and amplitude of a sound wave?
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Answer
(a) Wavelength - Wavelength can be defined as the distance between two consecutive rarefactions or two consecutive compressions. The SI unit of wavelength is metre (m).
(b) Frequency - Frequency is defined as the number of oscillations per second. The SI unit of frequency is hertz (Hz).
(c) Amplitude - Amplitude can be defined as the maximum height reached by the trough or crest of a sound wave.
(d) Time period - The time period is defined as the time required to produce one complete cycle of a sound wave.
2. How are the wavelength and frequency of a sound wave related to its speed?
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Answer
Wavelength, speed, and frequency are related in the following way:
Speed $=$ Wavelength $x$ Frequency
$v=\lambda v$
3. Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is $440 m / s$ in a given medium.
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Answer
Given that,
Frequency of sound wave $=220 Hz$
Speed of sound wave $=440 m / s$
Calculate wavelength.
We know that
Speed $=$ Wavelength $\times$ Frequency
$v=\lambda v$
$440=$ Wavelength $\times 220$
Wavelength $=440 / 220$
Wavelength $=2$
Therefore, the wavelength of the sound wave $=2$ metres
4. A person is listening to a tone of $500 Hz$ sitting at a distance of 450 $m$ from the source of the sound. What is the time interval between successive compressions from the source?
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Answer
The time interval between successive compressions from the source is equal to the time period, and the time period is reciprocal to the frequency. Therefore, it can be calculated as follows:
$T=1 / F$
$T=1 / 500$
$T=0.002 s$
