Question 1 :
Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?
Question 2 :
Does sound follow the same laws of reflection as light does?
Question 3 :
If the time gap between the original sound and reflected sound received by the listener is around _____ , only then the echo can be heard
Question 5 :
Sound waves are characterised by the motion of particles in the medium and are called mechanical waves. TRUE OR FALSE?
Question 7 :
Megaphones or loudhailers, horns, musical instruments such as trumpets and shehanais, are all designed to send sound in a particular direction without spreading it in all directions. TRUE OR FALSE?
Question 10 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2abf59b460d7261f602.jpg' />
In the above curve, half the wavelength is ___.
Question 13 :
A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? (Given, g = 10 m$s^{\left(-2\right)}$ and speed of sound = 340 m/s ).
Question 14 :
A peak is called the trough and a valley is called the crest of a wave. TRUE OR FALSE?
Question 15 :
A ship sends out ultrasound that returns from the seabed and is detected after 3.42 s. If the speed of ultrasound through seawater is 1531 m/s, what is the distance of the seabed from the ship?
Question 16 :
The matter or substance through which sound is transmitted is called a medium. TRUE OR FALSE?
Question 18 :
Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?
Question 19 :
Ultrasonic waves are made to reflect from various parts of the heart and form the image of the heart. This technique is called?
Question 21 :
Earthquake produces which kind of sound before the main shock wave begins ___.
Question 22 :
Sound produced by a thunderstorm is heard 10 s after the lightning is seen. Calculate the approximate distance of the thunder cloud if speed of sound = 340 $ ms^{-1}$.
Question 23 :
Establish the relationship between speed of sound (u), its wavelength ($\lambda$) and frequency (v).
Question 27 :
Sound is a form of energy which produces a sensation of hearing in our ears. TRUE OR FALSE?
Question 28 :
At the end of the auditory canal there is a thin membrane called?
Question 29 :
__________ is a kind of rapid to and fro motion of an object.
Question 31 :
In the inner ear, the pressure variations are turned into electrical signals by?
Question 32 :
How do you think sound is produced by your school bell?
Question 33 :
A key of a mechanical piano struck gently and then struck again but much harder this time. In the second case ____.
Question 34 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2acf59b460d7261f604.jpg' />
In the above graph, which of the 2 waves, (a) and (b), representing human voice is likely to be male voice? Give reason for your answer.
Question 35 :
Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the string suitably. By doing so, what is he adjusting?
Question 36 :
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?
Question 37 :
If we shout or clap near a suitable reflecting object such as a tall building or a mountain, we will hear the same sound again a little later. This sound which we hear is called an _______________.
Question 39 :
For hearing a distinct sound, the time interval between the original sound and the reflected one must be at least _______ s.
Question 40 :
Ultrasounds are used extensively in industries and for medical purposes.
TRUE OR FALSE?
Question 41 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2adf59b460d7261f605.jpg' />
In the above figure, find angle 'x' for hearing the loudest ticking sound heard by the ear.
Question 42 :
A submarine emits a sonar pulse, which returns from an underwater cliff in 1.02 s. If the speed of sound in salt water is 1531 m/s, how far away is the cliff?
Question 43 :
A sound wave travels at a speed of 339 m/s. If its wavelength is 1.5 cm, what is the frequency of the wave?
Question 44 :
An echo is heard in 3 s. What is the distance of the reflecting surface from the source, given that the speed of sound is $342 m s^{–1}$?
Question 45 :
Does sound follow the same laws of reflection as light does?
Question 46 :
Why is the ceiling and wall behind the stage of good conference halls or concert halls made curved?
Question 47 : <img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1d2aaf59b460d7261f601.png' />
Which of the following is best represented according to the above given graphical representations ?
Question 48 :
Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.
Question 50 :
A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? Given, $g = 10 m s^{–2}$ and speed of sound $=340 m s^{–1}$.
