Question 5 :
Trees must be removed from the road sides and around buildings to reduce the harmful effects of noise pollution.

Question 12 :
The amplitude of vibration and its frequency can change suddenly in a:

Question 13 :
State whether given statement is True or False<br/>Noise pollution can cause partial hearing impairment. <br/>

Question 14 :
The frequency of a wave is $5\;Hz$. Then the wave is a/an (type of wave)

Question 15 :
The sounds having frequency less than 20 Hz are called ultrasonics.<br/>

Question 16 :
Assertion: Ultrasonic waves are longitudinal waves of frequency grater than $20,000 Hz$ Reason: The maximum frequency of audible sound waves is $20,000 Hz$

Question 18 :
What is the approximate range of audible sound frequencies for a human with good hearing?

Question 20 :
State whether given statement is True or False :<br/>Music for one person can be noise to others.

Question 21 :
To reduce noise pollution, which of the following devices must be installed on the vehicles ?

Question 22 :
The loudness or softness of a sound is determined basically by ________.

Question 23 :
In the following sentence. say 'True' and 'False'<br/>$(a)$ Sound can't travel in vacuum (T/F)<br/>$(b)$ The number of oscillations per second of a vibrating object is called its time period. (T/F)<br/>$(c)$ If the amplitude of vibration is large, sound is feeble. (T/F)<br/>$(d)$ For human ears, the audible range is 20Hz to 20,000Hz. (T/F)<br/>$(e)$ The lower the frequency of vibration, the higher is the pitch.<br/>$(f)$ Unwanted or unpleasant sound is termed as music. (T/F)<br/>$(g)$ Noise pollution may cause partial hearing impairment. (T/F)

Question 25 :
The amplitude of vibration and its frequency can changed suddenly in a :

Question 30 :
Human ears can sense sound wave travelling in air having wavelength of ................... .<br>

Question 32 :
The property of ultrasonic waves used in manufacturing emulsion for photographic films is its, _____________

Question 33 :
Which of the following are true for noise pollution?<br/>a)&#160;Noise pollution is unpleasant and discomforting.<br/>b)&#160;Noise pollution can cause health problems.<br/>c)&#160;Long term exposure to loud noises can cause temporary or ever&#160;permanent hearing impairment.d)&#160;Noise pollution is caused by extremely loud sounds.

Question 34 :
Assertion: Ultrasonic waves are longitudinal waves of frequency greater than 20,000 Hz. Reason: The maximum frequency of audible sound waves is 20,000 Hz.

Question 36 :
<p>Which of the following frequency of sound can be heard by a dog but not by a man?</p>

Question 37 :
<p>Which of the following is not a characteristic of a&#160;musical sound?</p>

Question 38 :
Assertion: Ultrasonic waves are longitudinal waves of frequency greater than 20,000 Hz. Reason: The maximum frequency of audible sound waves is 20,000 Hz.

Question 39 :
<p>Fill in the blanks:</p><p>1) Perceived fundamental frequency of sound = ?<br/></p><p>2) Quality of sound = ?<br/></p>

Question 42 :
State whether given statement is True or False :<br/>Sound from outer space adds to the noise pollution on the earth.<br/>

Question 43 :
<p>Which of the following measure can be taken to control noise pollution in our surroundings.</p>

Question 45 :
State whether given statement is True or False<br/>Both Noise and Music when very loud can be damaging to human ears.<br/>

Question 49 :
State whether given statement is True or False<br/>Water animals are also subjected to noise pollution.<br/>

Question 50 :
<p>Three different vibrating bodies produce three types of sounds X, Y and Z. Sounds X and Y cannot be heared by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in for monitoring nuclear reactor.The sound similar to that which is produced during an earthquake before the main shock wave is generated. What type of sounds are (i) X (ii) Y, and (iii) Z?</p>

Question 51 :
Assertion: Every vibrating body is a source of sound Reason: All sounds are audible

Question 54 :
State whether the following statement is true or False:Human beings and most animals like birds, beer, bees, mosquitoes produce sound by the vibrations of their vocal chords.

Question 55 :
How does a sound making object differ from one that is silent?

Question 56 :
Assertion: In the case of a stationary wave, a person hear loud sound at the nodes as compared to the antinodes. Reason: In a stationary wave all the particles of the medium vibrate in phase.

Question 57 :
The lowest pitch out of the following sources is that of a

Question 61 :
In the following statements , tick (T) against those which are true , and False against those which are false :<br>Sound generate due to vibration in objects.

Question 62 :
If we strike a water-filled bowl with spoon, then why there is variation in the sound produced due to change in water level ofthe bowl?

Question 64 :
When we hold a thin plastic ruler firmly on a bench:

Question 65 :
On the basis of following features identify correct option:<br>I. It is the characteristic of a sound.<br>II. It distinguishes an acute or a shrill note from a dull or flat note.

Question 67 :
Sound waves having the following frequency are audible to human beings:<br>

Question 68 :
If a vibrator strikes the water $50$ times in $5s$, then the frequency of wave is

Question 71 :
The membrane of a drum vibrates to produce sound. Similarly the string of a sitar vibrates to produce sound. Based on these two examples answer the following question. Which part of a whistle vibrates to produce sound?

Question 73 :
Assuming that the period of vibration of a tuning fork depends upon the length $l$ of its prongs density $\rho$ of its material and the elastic constant $E$ of its material what would be the formula for the period of its vibration.

Question 75 :
A key of a mechanical piano struck gently and then struck again but muchharder this time. In the second case<br>

Question 76 :
When we hear a sound, we can identify it source from

Question 77 :
Two tuning forks of frequency 256 and 258 vibrating per second are sounded together, then time interval between consecutive maxima heard by the observer is.

Question 78 :
The persistence of hearing for human beings is not more than

Question 79 :
The sensation of sound persists in the human brain for about ______________ of a second.

Question 81 :
When tuning a violin, a string is tightened. The musical note being played on the string becomes higher in pitch.

Question 82 :
Assertion: The quality of sound and pitch remain the same when the closed end or a pipe is suddenly opened. Reason: When the closed end is opened the pitch is doubled and the quality becomes changed.

Question 83 :
Different musical instruments sound different even when they play a note with the same pitch.

Question 84 :
How does the sound produced by a vibrating object in a medium reach your ear?

Question 87 :
A transverse wave of frequency 100 Hz passes through water. The refractive index of water is 1.33, what will be the frequency of the wave in water

Question 88 :
The range of the wavelength of audible sound that travels with a velocity of 330 m s$^{-1}$ at 0$^{\circ}$ C is&#160;16.5 m - 16.5 mm.<br/>

Question 89 :
In the following statements , tick (T) against those which are true , and False against those which are false :<br>The unit of loudness of sound is decibel (db)

Question 90 :
<p>Before playing the orchestra in a musical concert, sitarist tries to adjust the tension and pluck the strings suitably. By doing so he is adjusting:</p>

Question 91 :
If the frequency of sound wave in air is doubled,its wavelength.

Question 93 :
The grandparents and parents of two-year old girl are playing with her in a room. A sound source produces a $28 kHz$ sound. Who in the room is most likely to hear the sound?

Question 94 :
<br/>A&#160;microwave and an ultrasonic sound wave have the same wavelength. Their&#160;frequencies are in the ratio (approximately)&#160;

Question 95 :
Which of the following properties of a sound wave determine its pitch?

Question 96 :
The frequency of a wave is 5 Hz. It refers to (type of wave)&#160;___________.

Question 97 :
Match the following and choose the correct option<table class="wysiwyg-table"><tbody><tr><td>A</td><td>String vibration</td><td>1.</td><td>Tabla</td></tr><tr><td>B</td><td>Membrane vibration</td><td>2.</td><td>Cymbals</td></tr><tr><td>C</td><td>Vibration of air</td><td>3.</td><td>Sitar</td></tr><tr><td>D</td><td>Vibration of plate</td><td>4.</td><td>Flute</td></tr></tbody></table>

Question 99 :
Frequency of vibration of a particle is 10 Hz. If the amplitude of vibration is doubled, what will be the change in frequency of vibration

Question 100 :
Echocardiography is used to diagnose heart diseases which utilises infrasonic waves.

Question 101 :
When a sound wave enters the ear, it sets the eardrum into oscillation, which &#160;in turn causes oscillation of 3 tiny bones in the middle ear called ossicles. This oscillation is finally transmitted to the fluid filled in inner portion of the ear termed as inner ear, the motion of the fluid disturbs hair calls within the inner ear which transmit nerve impulses to the brain with information that a sound is present. The three bones present in the middle ear are named as hammer, anvil and stirrup. Out of these the stirrup is the smallest one and this only connects the middle &#160;ear to inner ear as shown in the figure below. The area of stirrup&#160;and its extent of connection with the inner ear limits the sensitivity of the human ear. Consider a person's eat whose moving part of the eardrum has an area of about 43 mm$^{2}$ and the area of stirrup is about 3.2 mm$^{2}$. The mass of ossicles is negligible. As a result, force&#160;&#160;exerted by sound wave in air on eardrum and ossicles is same as the force exerted by ossicles on the inner ear. Consider a sound wave having maximum pressure fluctuation of $3\times10^{-2}$&#160;Pa from its normal equilibrium pressure value which is wqual to $10^{5}$ Pa. Frequency of sound wave is 1200 Hz.&#160;<br/>Data: Velocity of sound wave in air is &#160;332 m/s. Velocity of sound wave in fluid (present in inner ear) is 1500 m/s. Bulk modulus of air is $1.42\times10^{5}$ Pa. Bulk modulus of fluid is $2.18\times10^{9}$ Pa.<br/><br/><br/>Find the pressure amplitude of given sound wave in the fluid of inner ear.&#160;

Question 102 :
A wave moves at a constant speed along a stretched string.<br>Mark the incorrect statement out of the following

Question 103 :
A sound of intensity $I$ is greater by $3.0103\ dB$ from another sound of intensity $10\ nW\ c{ m }^{ -2 }$ . The absolute value of intensity of sound level $I$ in ${ Wm }^{ -2 }$ is :<br/>