Advertisements
Advertisements
प्रश्न
What is a megaphone ? Name the principle on which a megaphone works.
Advertisements
उत्तर
A megaphone is a large cone-shaped device used for amplifying and directing the voice of a person who speaks into it. A megaphone works on the principle of multiple reflections of sound. It is used for addressing a small gathering of people.
APPEARS IN
संबंधित प्रश्न
How is the frequency of a stretched string related to its length?
A certain sound has a frequency of 256 hertz and a wavelength of 1.3 m.
1) Calculate the speed with which this sound travels
2) What difference would be felt by a listener between the above sound and another sound traveling at the same speed, but of wavelength 2.6 m?
State two factors on which the speed of a wave travelling in a medium depends.
The following diagram shows three ways in which the string of an instrument can vibrate.
(a) which of the diagram shows the principal note?
(b) which has the frequency four times that of the first?
(c) what is the ratio of the frequency of the vibration in (i) and (ii)?
Name the principle on which a soundboard works.
Explain how is the principle of echo used by
(a) The bat during its flight at night,
(b) The dolphin to locate small fish as its prey.
Explain reflection at the boundary of a rarer medium.
Explain Reflection at curved surfaces.
The direction of the incident sound, the direction of reflected sound, and the normal are in different Planes.
