Perception of Sound

Q.

The loudness and pitch of a sound depends on

1. Frequency and velocity

2. Intensity and frequency

3. Intensity and velocity

4. Frequency and number of harmonics

Q.

A man $X$ can hear only upto 10 kHz and another man $Y$ upto 20 kHz. A note of frequency 500 Hz is produced before them from a stretched string. Then

1. Both will hear sounds of same pitch and same quality

2. Both will hear sounds of same pitch but different quality

3. Both will hear sounds of different pitch but same quality

4. Both will hear sounds of different pitch and different quality

Q. A plane wavefront strikes the convex mirror the emergent wavefront will be

1. Plane
2. Converging
3. Cylindrical
4. Diverging

Q. Characteristic of sound which enables us to distinguish between two sound of same loudness and pitch :

1. amplitude
2. a and b
3. quality
4. timbre

Q. A tuning fork of frequency $480Hz$ is used in an experiment for measuring speed of sound $\left(v\right)$ in air by resonance tube method. resonance is observed to occur at two successive lengths of the air column, $l_1=30cm$ and $l_2=70cm$. Then $v$ is equal to:

1. $332m{s}^{-1}$
2. $379m{s}^{-1}$
3. $338m{s}^{-1}$
4. $384m{s}^{-1}$

Q. Two tones of frequencies $n_1$ and$n_2$ are sounded together.The beats can be heard distinctly when

1. $10<(n_1-n_2)<20$
2. $5<(n_1-n_2)>20$
3. $5<(n_1-n_2)<20$
4. $0<(n_1-n_2)<10$

Q.

What are the two main properties of a sound?

Q. Name the factor that determines Quality of the note.

Q. Fill in the blanks with suitable words.
$\left(a\right)$ Time taken by an object to complete one oscillation is called ______________.
$\left(b\right)$ Loudness is determined by the _______________ of vibration.
$\left(c\right)$ The unit of frequency is ______________.
$\left(d\right)$ Unwanted sound is called ______________.
$\left(e\right)$ Shrillness of a sound is determined by the ______________ of vibration.

1. Time period, Hertz, Noise, Frequency, Amplitude
2. Time period, Amplitude, Hertz, Noise, Frequency
3. Time period, Amplitude, Hertz, Frequency, Noise
4. Amplitude, Hertz, Noise, Frequency, Time period

Q. A sound is played on a flute A sound of same pitch is played on a trumpet then the frequency and speed of two sound waves respectively at the same place are:

1. Different, different
2. Same, same
3. Different, same
4. Same, different

Q. In the following table, match the column B according to column A :

	Column (A)		Column (B)
(i)	Pitch	(a)	waveform
(ii)	Quality	(b)	Frequency
(iii)	Loudness	(c)	Intensity

1. (i) - (b), (ii) - (a), (iii) - (c)
2. (i) - (c), (ii) - (b), (iii) - (a)
3. (i) - (a), (ii) - (b), (iii) - (c)
4. (i) - (b), (ii) - (c), (iii) - (a)

Q.

Each of the properties of sound listed in column A primarily depends on one of the quantities in column B. Choose the matching pairs from two columns:

Column A Column B

Pitch Waveform

Quality Frequency

Loudness Intensity

1. Pitch-waveform; Quality-frequency; Loudness-intensity
2. Pitch-frequency; Quality-waveform; Loudness-intensity
3. Pitch-intensity; Quality-waveform; Loudness- frequency
4. Pitch-waveform; Quality- intensity; Loudness-frequency

Q. Sound wave with frequency above 200 kHz are

1. Audiable waves
2. Ultra Sound waves
3. Infra Sound waves
4. None of these

Q. Find the minimum and maximum wavelengths of sound in water that is in the audible range (20 - 20000 Hz) for an average human ear. Speed of sound in water = 1450 m s${}^{-1}$.

1. 100 cm, 1000 m

2. 7.25 cm, 72.5 m

3. 1 cm, 1 m

4. None of the above

Q. Beats are the result of

1. Diffraction
2. Destructive interference
3. Constructive and destructive interference
4. Superposition of two waves of nearly equal frequencies

Q. Sound is produced by a vibrating source . Why then a vibrating pendulum does not produce any sound ?

Q. As the natural frequency of the system is approached, the amplitude of the oscillations becomes ________. Fill in the bank.

1. smaller
2. constant
3. indeterminate
4. greater

Q. Two waves having sinusoidal waveforms have different wavelengths and different amplitude. They will be having

1. Same quality and different intensity
2. Same pitch and different intensity
3. Different quality and different intensity
4. Same quality and different pitch

Q. A person can be identified by the quality of sound produced by him. The characteristic of a sound can be determined by:

1. amplitude
2. frequency
3. loudness
4. all of the above

Q. In AM waves, the amplitude of each side band frequency is:

1. $E_c$
2. ${mE}_c$
3. $\frac{{mE}_c}{2}$
4. $2m{E}_c$

Q. Name the characteristics of sound related to its frequency.

Q. How does the two sounds of same loudness and same pitch produced by different instruments differ ? Draw diagrams to illustrate your answer.

Q. The frequency of the third harmonic of a closed organ pipe is equal to which of the overtone

1. First
2. Second
3. Fourth
4. None of these

Q. (b) Pitch