How does the sound produced by a vibrating object in a medium reach your ear?
view answer >Guess which sound has a higher pitch: guitar or a car horn?
view answer >Suppose you and your friend are on the moon. Will you be able to hear any sound produced by your friend?
view answer >Which wave property determines
(a) Loudness
(b) Pitch?
view answer >How are the wavelength and frequency of a sound wave related to its speed?
view answer >Name the type of waves which are used by astronauts to communicate with one another on moon (or in outer spece).
view answer >A submarine sends 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?
view answer >Why are the ceiling of concert halls curved?
view answer >Calculate that wavelength of a sound wave frequency is 220 Hz and speed is 440 m/s in a given medium.
view answer >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 sources?
view answer >An echo returned 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?
view answer >Two children are at opposite ends of an aluminium rod. One strikes the end of rod with a stone. Find the ratio of times taken by sound wave in air and in aluminium to reach the second child (Given: Speed of sound in air = 346 m/s; Speed of sound in aluminium = 6240 m/s)
view answer >Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen. Why?
view answer >What type of wave is represented :
(a) by density-distance graph?
(b) by displacement-distance graph?
view answer >State the general name of the waves on which the particles of the medium vibrate:
(i) in the same direction as wave.
(ii) at right angles to the direction of wave.
view answer >What is sonar? Explain its use.
view answer >The flash of a gun is seen by a man 3 seconds before the sound is heard. Calculate the distance of the gun from the man (Speed of sound in air is 332 m/s).
view answer >Explain the terms ‘crests’ and ‘troughs’ of a wave? What type of waves consist of crests and troughs?
view answer >What are longitudinal waves and transverse waves? Explain with the help of labelled diagrams.
view answer >What is loudness of sound? What factors does it depend on?
view answer >What is reverberation? How can it be reduced?
view answer >Does sound follow the same laws of reflection as light does? Explain.
view answer >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 remains the same. Do you hear echo sound on a hotter day?
view answer >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.
view answer >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? Giving g = 10 ms-2 and speed of sound = 340 ms-1.
view answer >Define the following terms:
(1) Echolocation
(2) Echocardiography, and
(3) Ultrasonography.
view answer >Define the terms ‘frequency’, ‘wavelength’ and ‘velocity’ of a sound wave. What is the relation between them?
view answer >Draw a neat and labelled diagram of the human ear. With the help of this diagram, explain the construction and working of the human ear.
view answer >A device called oscillator is used to send waves along a stretched string. The string is 20 cm long, and four complete waves fit along its length when the oscillator vibrates 30 times per second. For the waves on the string:
(a) what is their wavelength?
(b) what is their frequency?
(c) what is their speed?
view answer >A sound producing body is at considerable distance from a man. There can be four different media W, X, Y and Z between the sound producing body and the man. The medium X brings the sound to man most quickly whereas medium Z tajes the maximum time. The time taken by medium W in bringing sound to man is less than that of X but more than that of Z. The medium Y, however, fails to bring the sound from the sound producing body to the man. Which medium could be the one:
(a) having no fixed shape and no fixed volume?
(b) having a fixed volume but no fixed shape?
(c) having the same composition as that on the moon?
(d) having a fixed shape and a fixed volume?
view answer >