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Sound

Why do we hear the sound produced by the humming bees while the sound
of vibrations of pendulum is not heard?

05/11/2024

Science

9th

Sound

A girl is sitting in the middle of a park of dimension 12 m × 12 m. On the
left side of it there is a building adjoining the park and on right side of the
park, there is a road adjoining the park. A sound is produced on the road
by a cracker. Is it possible for the girl to hear the echo of this sound?
Explain your answer.

05/11/2024

Science

9th

Sound

Before playing the orchestra in a musical concert, a sitarist tries to adjust
the tension and pluck the string 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

05/11/2024

Science

9th

Sound

Infrasound can be heard by
(a) dog
(b) bat
(c) rhinoceros
(d) human beings

05/11/2024

Science

9th

Sound

Earthquake produces which kind of sound before the main shock wave begins
(a) ultrasound
(b) infrasound
(c) audible sound
(d) none of the above

05/11/2024

Science

9th

Sound

When we change feeble sound to loud sound we increase its
(a) frequency
(b) amplitude
(c) velocity
(d) wavelength

05/11/2024

Science

9th

Sound

Sound travels in air if
(a) particles of medium travel from one place to another
(b) there is no moisture in the atmosphere
(c) disturbance moves
(d) both particles as well as disturbance travel from one place to another.

05/11/2024

Science

9th

Sound

In SONAR, we use
(a) ultrasonic waves
(b) infrasonic waves
(c) radio waves
(d) audible sound waves

05/11/2024

Science

9th

Sound

A key of a mechanical piano 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 pitch will also be higher
(c) sound will be louder but pitch will be lower
(d) both loudness and pitch will remain unaffected

05/11/2024

Science

9th

Sound

Note is a sound
(a) of mixture of several frequencies
(b) of mixture of two frequencies only
(c) of a single frequency
(d) always unpleasant to listen

05/11/2024

Science

9th