Sound Worksheet-10

Sound Worksheet-10

 

  1. Name the device used by doctors to listen to our heartbeats.

 

  1. What is the shape of a soundboard kept behind the speaker on the stage of a big hall?

 

  1. Name two sound absorbing materials (or objects) which can make our big room less echoey.

 

  1. Can we hear (a) infrasonic waves (b) ultrasonic waves?

 

  1. What name is given to the sound waves of frequency too low for humans to hear?

 

  1. What name is given to the sound waves of frequency too high for humans to hear?

 

  1. What type of sound waves are produced by a vibrating simple pendulum?

 

  1. What happens to the pitch of a sound if its frequency increases?

 

  1. What happens to the loudness of a sound if its amplitude decreases?

 

  1. What name is given to sound waves of frequencies higher than 20 kHz?

 

  1. On which day, a hot day or a cold day, an echo is heard sooner? Give reason for your answer.

 

  1. In which medium, air or water, an echo is heard much sooner? Why?

 

  1. What is reverberation? What will happen if the reverberation time in a big hall is too long?

 

  1. How can reverberations in a big hall or auditorium be reduced?

 

  1.  Why do we hear more clearly in a room with curtains than in a room without curtains?

 

  1. What is a megaphone? Name the principle on which a megaphone works.

 

  1. What is a bulb horn? Name the principle on which a bulb horn works.

 

  1. What is a stethoscope? Name the principle on which a stethoscope works.

 

  1. What is a soundboard? Explain the working of a soundboard with the help of a labelled diagram.

 

  1. What is meant by the 'loudness' of sound ? On what factor does the loudness of a sound depend?

 

Answer:

  1. stethoscope

 

  1. Concave

 

 

  1. no

 

  1. Infrasonic

 

  1. Ultrasound

 

  1. Infrasonic sound waves

 

 

 

  1. Ultrasonic sound waves

 

  1. Hot day, because the speed of sound is more on a hot day.

 

  1. Water because speed of sound is more in liquid.

 

 

 

 

 

 

  1. Reflection of sound