Question 1 :
Which experiment shows that sound needs a material medium for its propagation?
Question 3 :
When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remain the same. Do you hear echo sound on a hotter day?
Question 4 :
If any explosion takes place at the bottom of a lake, what type of shock waves in water will take place?
Question 5 :
Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.
Question 6 :
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 7 :
Guess which sound has a higher pitch: guitar or car horn?
Question 8 :
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 10 :
Earthquake produces which kind of sound before the main shock wave begins ___.
Question 12 :
Ultrasounds are used extensively in industries and for medical purposes.
TRUE OR FALSE?
Question 15 :
How does the sound produced by a vibrating object in a medium reach your ear?
Question 16 :
A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.
Question 17 :
The persistence of sound in an auditorium is the result of repeated reflections of sound and is called __________
Question 18 :
__________ is a kind of rapid to and fro motion of an object.
Question 19 :
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 20 :
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 22 :
Sound is a form of energy which produces a sensation of hearing in our ears. TRUE OR FALSE?
Question 23 :
If velocity of sound in air is $340ms^{-1}$, calculate wavelength when frequency is 256 Hz.
Question 24 :
Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?
Question 25 :
Which characteristic of the sound helps you to identify your friend by his voice while sitting with others in a dark room?
Question 27 :
If you lace a bell into a vacuum chamber with no air in it , will you still be able to hear the sound of the bell ?
Question 28 :
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 $=340 m s^{–1}$.
Question 29 :
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? (Speed of sound in air = 330 m/s)
Question 31 :
For hearing a distinct sound, the time interval between the original sound and the reflected one must be at least _______ s.
Question 32 :
________ is a medical instrument used for listening to sounds produced within the body, mainly in the heart or lungs.
Question 34 :
The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?
Question 35 :
How defects in a metal block can be detected using ultrasound?
Question 37 : <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 39 :
In which type of propagation the particles do not move from one place to another but they simply oscillate back and forth about their position of rest parallel to the direction of wave propagation?
Question 40 :
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 41 :
A sound wave travels at a speed of $339 ms^{–1}$. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?
Question 44 :
When we change feeble sound to loud sound, we increase its ___.
Question 46 :
Why is the ceiling and wall behind the stage of good conference halls or concert halls made curved?
Question 47 :
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 48 :
A person clapped his hands near a cliff and heard the echo after 2 s. What is the distance of the cliff from the person if the speed of the sound, v is taken as $346 m s^{–1}$?
Question 49 :
Does sound follow the same laws of reflection as light does?
Question 50 :
A wave is a disturbance that moves through a medium when the particles of the medium set neighbouring particles into motion. TRUE OR FALSE?
