Q87 of 199 Page 209

In an experiment, Anhad studies sound waves. He sets up a loudspeaker to produce sound as shown below:

Picture


Anhad adjusts the signal to the loudspeaker to give a sound of frequency 200 Hz.


(a) What happens to the air in-between Anhas and the loudspeaker?


(b) Explain how Anhad receives sound in both ears.

(a) When Anhad adjusts the signal to the loudspeaker to give a sound of frequency 200 Hz then the air between Anhad and the loudspeaker vibrates with the frequency of 200 Hz.

(b) Both the ear of Anhad recives the sound. His right ear recives the sound by the sound waves coming directly from the loudspeaker (through air)where as his left ear recives the sound from sound waves reflected from the wall of classroom.


More from this chapter

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85

The drawing shoes a ship 800 m from a cliff. A gun is fired on the ship. After 5 seconds the people at the front of the ship hear the sound of the gun again.

(a) What is the name of this effect?


(b) What happens to the sound at the cliff?


(c) How far foes the sound travel in 5 seconds?


(d) Calculate the speed of sound.

 86

Consider the following sound waves marked A, B, C and D:

(a) Which two waves represent sounds of the same loudness but different pitch?


(b) Which two waves represent sounds of the same frequency but different loudness?


(c) State whether all these sound waves have been produced by the same vibrating body or different vibrating bodies?


(d) Which vibrating body/bodies could have generated the sound waves shown here?

 88

Figure X showa a trace of a sound wave produced by a particular tuning fork:

Picture



(a) On the graph paper given in Figure Y, draw a trace of the sound wave which has higher frequency than that shown in Figure X.


(b) On the graph paper shoen in Figure Z, draw a trace of the sound wave which has a larger amplitude than that shown in Figure X.

 89

Three different vibrating objects produce three types of sounds X, Y and Z. Sounds X and Y cannot be heard by a man having normal range of hearing but sound Z can be heard easily. The sound X is used in hospitals to break kidney stones of a patient into fine grains whioch then get flushed out with urine. The sound Y is similar to that which is produced during an earthquake before the main shock wave is generated.

(a) What type of sounds are (i) X, (ii) Y, and (iii) Z?


(b) Name one device which can produce sound like X.


(c) Name one device in a science laboratory which can produce sound like Y.


(d) Name one device in our homes which can produce sound like Z.


(e) What is the frequency range of sounds like Z?