Olympiad Test: Sound- 1 - Class 9 MCQ

v=2d/t = (2*480)/2 = 480 ms^-1

v=2d/t

Or, d=(v×t)/2

=1500×.4/2

=300m

V = 2d/t or d = (v× t)/2

= (1450×4)/2= 2900 m or 2.9 km.

v= 2d/t or t=2d/v

=(2 × 660)/330

=4s

The speed of a wave is related to its frequency and wavelength by the following formula:

speed = frequency x wavelength

In this case, the speed of the wave is 340 m/s, the frequency is 1700 Hz, and we want to find the wavelength in cm. We can rearrange the formula above to solve for wavelength:

wavelength = speed / frequency

Substituting in the known values, we get:

wavelength = 340 m/s / 1700 Hz wavelength = 0.2 m

Converting this to cm, we get:

wavelength = 0.2 m x 100 cm/m wavelength = 20 cm

Thus, the correct answer is 20.

T=1/v=1/25

= 0.04sec.

Earthquakes produce infra-sound before the main shock wave.

Infrasound is a low-frequency sound. It is a sound that is lower in frequency than 20 Hz (hertz) or cycles per second, the normal limit of human hearing. Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. The ear is the primary organ for sensing infra-sound, but at higher intensities it is possible to feel infra-sound vibrations in various parts of the body.

Bats emit a series of high-frequency sounds from their mouths or nostrils that bounce off objects and then return to the ears of bats. These high-frequency sounds are called ultrasonic waves. with the help of the reflection of ultrasonic waves, bats detect the obstacles in their path.

Solids have the highest velocity of sound in them among all phases so a ground being a solid has a very high velocity of sound.

A violin and a flute may both be played at the same time in an orchestra.

Both sounds travel through the same medium, that is, air and arrive at our ear at the same time.

Both sounds travel at the same speed irrespective of the source.

But the sounds we receive are different. This is due to the different characteristics associated with the sound.

Pitch is one of the characteristics. Similarly, the sitarist adjusts the frequency of sitar according to other musical instruments.