‘Note’ os a sound:

A. of a mixture of several frequencies

B. of mixture of only two frequencies

C. of a single frequency

D. always unpleasant to listen to

Which kind of sound is produced in an earthquake before the main shock wave begins?

A. ultrasound B. infrasound

C. audible sound

D. none of the above

Before playing the orchestra in a musical concert, a sitarist tries to adjust the tension and pluck the strings suitably. By doing so he is adjusting:

A. intensity of sound only

B. amplitude of sound only

C. frequency of the sitar string with the frequency of other musical instruments

D. loudness of sound

A key of mechanical piano is first struck gently and then struck again but much harder this time. In the second case:

A. sound will be louder but pitch will not be different

B. sound will be louder and the pitch will also be higher

C. sound will be luder but pitch will be lower

D. both loudness and pitch will remain unaffected

one of the following can hear infrasound. This one is :

A. dog B. bat

C. rhinoceros D. humans