Frank solutions for Physics [English] Class 9 ICSE chapter 7 - Sound [Latest edition]

Is sound a form of energy?

How is sound produced?

Can sound travel through vacuum?

Can sound propagate in solids and liquids?

Can we produce sound in vacuum?

State the main factors on which the speed of sound in a medium depends.

What is the approximate value of the speed of sound in air at N.T.P.?

Compare approximately the speed of sound in air, water, and iron.

How does the speed of sound depend on (i) Amplitude, and (ii) Wavelength?

On placing your ear close to an iron railing which is tapped some distance away, sound is heard twice. Explain, why?

What causes sound in air?

What is the ratio of speed of light to speed of sound?

State the effect of pressure on the speed of sound in air.

How does the speed of sound in air vary with the temperature?

he sound of an explosion on the surface of a lake is heard by a boatman 120 m away and by a diver 120 m below the point of explosion. Out of the two persons, who would hear the sound first? Why?

Describe a simple experiment to determine the speed of sound in air.

How do the following factor affect the speed of sound in air?
Moisture in air.

How do the following factor affect the speed of sound in air?
Pressure in air.

How do the following factor affect the speed of sound in air?
Temperature of air

The time interval between a lighting flash and the first sound of thunder was found to be 6 s. If the speed of sound in air is 330 ms^-1, find the distance of the flash from the observer.

A person fires a gun and other boy at a distance hears the sound of the fire 2.5 s after seeing the flash. If the speed of sound in air is 330 ms^-1, find the distance between the boys.

What do you mean by the frequency of sound?

What is the SI unit of frequency?

Define one hertz.

What is the audible range of frequency?

Can we hear sounds of frequencies:
Less than 20 Hz

Can we hear sounds of frequencies:
More than 20 KHZ

Does audible range of frequency vary from person and also with the age of the person?

What are infrasonic and ultrasonic sounds?

Is the energy carried by the ultrasound very high or very low?

What is echocardiography?

What does SONAR stand for? Where do we make use of SONAR?

How are bats able to avoid obstacles in their way?

What type of sound is produced by elephants and whales?

Do all animals have same ranges of audible frequencies?

What do you mean by an echo?

What is echolocation? How do animals make use of this phenomenon?

State three important uses of echolocation.

What are hearing aids?

State the main components of a hearing aid.

Describe a simple method to find the depth of a submerged ship.

State the properties of ultrasound that make it useful.

Name the sound of the frequency given below:

10 Hz 

Name the Sound of the Frequency Given Below:
200 Hz

Name the Sound of the Frequency Given Below:
2000 Hz

Name the Sound of the Frequency Given Below:
45 kHz

Can you hear each other in a dark room?

What causes sound? 

Is sound a form of energy?

Can sound travel through vacuum?

Does sound require a material medium for transmission?

Name the factors on which the speed of sound depends.

What is the effect of wavelength and amplitude on the speed of sound?

What is the value of sound of room temperature?

Is the speed of sound different in different media?

Does the speed of sound in a gas depend on the pressure of the gas?

Write the formula for speed of sound in a gas using Laplace correction.

Does the speed of sound depend upon the direction of wind?

What are ultrasonic?

What does SONAR stand for?

Can you hear the sound produced due to the vibrations of second's pendulum?

Does SONAR make use of infrasonic sound?

Does ultrasonic in a medium travel faster than the audible sound?

Is it possible to hear your friend's voice in vacuum? Give reason for your answer.

What are the requisites of the medium for the propagation of sound? Briefly, explain them.

What cause sound? Why do we require a material medium for the transmission of sound?

What is the effect of temperature and pressure on the speed of sound in a gas?

What is the effect of wavelength and amplitude on the speed of sound?

Explain the effect of density on the speed of sound.

What is sound? Explain with example how does sound travel in a medium.

Compare approximately the speed of sound in air and steel.

The smoke from the gun barrel is seen 2 second before the explosion is heard. If the speed of sound in air is 350 ms^-1, calculate the distance of observer from the gun.

Does light travel faster in air than in water? Why?

Why does the flash of lighting reach earlier than the sound of thunder?

The sound of which of the following frequency is audible to us?
2 Hz, 1000 Hz, 200 kHz, 8 MHz

Describe in brief, with the aid of a sketch diagram, an experiment to demonstrate that a material medium is necessary to transmit sound.

State three characteristics of the medium required for the propagation of sound.

Describe a simple experiment to determine the speed of sound in air.

What are ultrasonic? State and explain two applications of ultrasounds.

How are sound waves produced? How are sound waves transmitted from one place to the other?

Distinguish between light and sound waves. What are the consequences of the large difference in the speed of sound and that of light? Briefly explain them.

How will the following factors affect the speed of sound in air:
Pressure of air.

How will the following factors affect the speed of sound in air:
Temperature of air.

How will the following factors affect the speed of sound in air:
Humidity.

How will the following factors affect the speed of sound in air:
Wind.

Explain how the principle of echo is used by
The bat during its flight at night

Explain how the principle of echo is used by
The dolphin to locate small fish as its prey.

A person hearing at one end of a long metal bar hears two distinct sounds when the other end is struck with a stone. Explain, giving scientific reasons