What is sound and how is it produced?

>

>

Chapter 11

NCERT

Class 9

Science

Solutions

1. What is sound and how is it produced?

Promo GIF

Question:

What is sound and how is it produced?

Answer:

Sound is a form of energy. Which is produced by the vibration of the medium. There are also methods of it’s generation-by striking, by pulling, by blowing, by rubbing etc.

It is clear from the following experiments that sound is produced by vibration.

More NCERT Questions

Download Free PDF

(All Q's of this Chapter solved)

question pointer

Explain how defects in a metal block can be defected using ultrasound?

question pointer

How is ultrasound used for cleaning?

question pointer

What is loudness of sound? What factors does it depend on?

question pointer

What is reverberation? How can it be reduced?

question pointer

A sound wave travels at a speed of 339 ms–1. If it’s wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?

question pointer

A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower, when is the splash heard at the top? Given g = 10 ms–2 and speed of sound = 340 ms–1.

question pointer

Give two practical applications of reflection of sound waves?

question pointer

When a sound is reflected from a distant object, an echo is produced. Let the distance between the reflecting surface and the source of sound production remains the same. Do you hear echo sound on a hotter day?

question pointer

Does sound follow the same laws of reflection as light does? Explain.

question pointer

The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?

question pointer

Two children are at opposite ends of an aluminum rod. One strikes the end of the rod with a stone. Find the ratio of times taken by the sound wave in air and in aluminum to reach the second child.

question pointer

A person has a hearing range from 20 Hz to 20 KHz. What are the typical wavelengths of sound waves in air corresponding to these two frequencies? Take the speed of sound in air as 344 ms–1?

question pointer

Flash and Thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen. Why?

question pointer

Which Characteristic of the sound helps you to identify your friend by his voice while sitting with others in a dark room?

question pointer

Why is sound wave called a longitudinal wave?

question pointer

Describe with the help of a diagram, how compressions and rarefactions are produced in air near a source of sound.

question pointer

What is the range of frequencies associated with (a) Infrasound? (b) Ultrasound?

question pointer

Why are the ceilings of concert halls curved?

question pointer

An echo is heard in 3s. What is the distance of the reflecting surface from the source, given that the speed of sound is 342 ms–1?

question pointer

In which of the three media, air, water or iron, does sound travel the fastest at a particular temperature?

question pointer

Distinguish between loudness and intensity of sound.

question pointer

A person is listening to a tone of 500 Hz sitting at a distance of 450 m from the source of the sound. What is the time interval between successive compressions from the source?

question pointer

Calculate the wavelength of a sound wave whose frequency is 220 Hz and speed is 440 m/s in a given medium.

question pointer

How are the wavelength and frequency of a sound wave related to its speed?

question pointer

What are wavelength, frequency, time period and amplitude of a sound wave?

question pointer

Guess which sound has a higher pitch: guitar or car horn?

question pointer

Which wave property determines (a) loudness, (b) pitch?

question pointer

Why are sound waves called mechanical waves?

question pointer

Explain how sound is produced N by your school bell.

question pointer

How does the sound produced by a vibrating object in a medium reach your ear?

Buy Latest Books

Teacher's Corner