Selina solutions for Concise Physics [English] Class 7 ICSE chapter 6 - Sound [Latest edition]

Write true or false for a given statement.

Sound can travel in a vacuum.

Write true or false for a given statement.

A sound is a form of energy.

Write true or false for a given statement.

Sound can only be produced by vibrating bodies.

Write true or false for a given statement.

Larger is the amplitude, feeble is the sound.

Write true or false for a given statement.

The frequency is measured in hertz.

Write true or false for a given statement.

Loudness depends on frequency.

Write true or false for a given statement.

Waveforms of two different stringed instruments can be the same.

Write true or false for a given statement.

Female voice is shriller than the male voice.

Write true or false for a given statement.

A ticking clock sound is heard late when heard through a metal.

 Fill in the blank. 

Sound is produced when a body ______.

Fill in the blank.

The number of times a body vibrates in one second is called its ______.

Fill in the blank.

The pitch of a sound depends on its ________.

Fill in the blank.

Sound can travel in a ______

Fill in the blank.

We can hear sounds of frequency in the range of _______

Fill in the blank.

Sound requires a ________ for propagation.

Fill in the blank.

Sound travels faster in ________ than in liquids.

Fill in the blank.

The sound heard after reflection is _______

Fill in the blank.

________ produces a sensation in ears.

Select the correct alternative :

We can distinguish a shrill sound from a flat sound by its

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We can hear sound of frequency

Select the correct alternative :

Sound cannot travel in

Select the correct alternative: 

The minimum distance required between the source and the reflector so as to hear the echo in air is

Select the correct alternative :

Wavelength is measured in

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The speed of sound in water is

Select the correct alternative : 

Sound travels the fastest in

What do you mean by a vibratory motion?

What is sound ?

How is sound produced ?

Describe an experiment to show that each source of sound is a vibrating body.

Name two sources of sound.

How do we produce sound ?

The bees do not have voice-boxes. How do they produce sound ?

Can sound travel through a vacuum ? Describe an experiment to explain your answer.

Describe an experiment to show that sound can travel in water.

Describe an experiment to show that sound can travel in a solid.

Can two person hear each other on moon’s surface ? Give reason to support your answer.

What is a longitudinal wave ?

Define the term Amplitude.

Define time period.

Define the following term:

Frequency

Write the audible range of frequency for the normal human ear.

What are ultrasonics? Can you hear the ultrasonic sound?

What are infrasonics? Can you hear them?

How does a bat make use of ultrasonics waves to find its way?

Name the two characteristics of sound which differentiate two sounds from each other.

On what factor does the loudness of a sound depend ?

How does the loudness of sound produced depend on the vibrating area of the body ?

The outer case of the bell in a temple is made big. Give a reason.

State the factors on which the pitch of a sound depends.

Differentiate between a high pitch sound and a low pitch sound.

How does a man’s voice differ from a woman’s voice ?

Name the characteristic which differentiates two sounds of the same pitch and same loudness.

You recognize your friend by hearing his voice on a telephone. Explain.

A musician recognizes the musical instrument by hearing the sound produced by it, even without seeing the instrument. Which characteristic of sound makes this possible ?

Describe an experiment to show the production of sound having low and high pitch.

How does a musician playing on a flute change the pitch of sound produced by it ?

Why are musical instruments provided with more than one string ?

How can the pitch of sound produced in a piano be changed ?

Explain why you can predict the arrival of a train by placing your ear on the rails without seeing it.

Write the approximate speed of sound in air.

Write the approximate speed of sound in water . 

Write the approximate speed of sound in steel.

During a thunderstorm, the sound of a thunder is heard after the lightning is seen. Why?

Describe an experiment to estimate the speed of sound in air.

Can sound travel through solids and liquids ? In which of these two does it travel faster ?

What do you mean by reflection of sound ?

State one use of reflection of sound.

What is echo ?

What minimum distance is required between the source of sound and the reflecting surface to hear an echo ? Give reason.

List four substances which are good absorbers of sound.

List the measures that you will take when designing a sound-proof room.

A boy fires a gun and another boy at a distance of 1020 m hears the sound of firing the gun 3 s after seeing its smoke. Find the speed of sound.

A boy on a hill A fires a gun. The other boy on hill B hears the sound after 4 s. If the speed of sound is 330 m s-1, find the distance between the two hills.