Telangana SCERT Class 8 Physical Science Chapter 5 Solution – Sound. Here in this post we provides Class 8 Physical Science Sound Telangana State Board Solution. Telangana State Board English Class VIII Medium Students can download this Solution to Solve out Improve Your Learning Questions and Answers.
Telanagana State Board Class 8 Physical Science Chapter 5 Sound Solution:
(1) How can you explain the sound has energy.
Ans: – Objects vibrate wile they are producing sound. You can feel these vibrations by touch the objects. That means sound energy is produced when an object vibrates. Sound energy is a form of mechanical energy. Sound waves are able to vibrate the diaphragm inside our ears. So we hear vibration means mechanical energy. If there is no energy, then the diaphragm doesn’t vibrate.
(2) What is the unit to measure the sound intensity.
Ans: – The intersity of sound is measure in dB (decibles)
(3) What are the differences between the noise and music? Explain.
Ans: – Sound pleasant to listen is called music.
But unpleasant sounds to listen are called noise.
We enjoy sounds in a musical way. But when the sound produced unbearable to hear like steel plate or utensil is dropped on the floor, it irritates us.
Music is a combination of sounds that are produced in an order and pleasant to hear.
Noise is an irregular combination of sounds which are ‘unpleasant’ to hear.
(4) Explain the sources which produce sound pollution in your surroundings.
Ans: – Sound pollution surroundings there are many sounds causing sound pollutions, like – sound of traffic, their horns at industries, sound at mines, sound during explosions and firing of trackers, loudspeakers etc…
There are some more sources of sound pollution in our houses like mixer/grinder, washing machines, vacuum cleaner, motors etc.
(5) Write your suggestions about reducing sound pollution.
Ans: – We cannot stop production of sound but we can reduce sound pollution by same measure.
Some stops which can be taken to reduce sound pollution –
(1) Attach silencers to bikes and other machines to reduce sounds.
(2) During the use of TV’s and music players tone down volume of sound.
(3) Plant huge amount of trees to reduce sound pollution
(4) Manufacture machines that work with less noise.
Application of concepts
(1) The sounds of crickets (insects) make us close our ears. Why?
Ans: – As pitch and frequency of sound made by cricket is so high which irritates a human ears. So we feel disco comfortable when we hear this high pitched noise. For this reason the sounds of crickets (insects) make us close our ears.
(2) Write the names of any three musical instruments that you know and explain how they produce sound.
Ans: – Musical instrument like Tabala, Plute, Harmonium.
The sounds of these musical instruments are produced by their district. Because of this it is easy for us to identify sounds severely from different instruments.
For example, in tabala, not only the stretched membrane but the air inside the hollow body also vibrates.
(3) Write any two slogans to reduce sound pollution.
Ans: – “Keep the noise down or the Noise will keep you down”
“Don’t be noisy, People Go Crazy!”
(4) Draw the figures depicting low amplitude and high amplitude.
(5) “Vibrations in a body produce sounds”. How do you prove it?
Ans: – Take a brass bell, now ping the bell and listen to the sound carefully. Then hold the bell tightly with your hand and you hear the sound from the bell.
Higher Order Thinking Questions
(1) What is the effect of humidity on quality of sound propagation? Is there any difference in propagation of sound in air during the summer and winter seasons? Discuss.
Ans: – Sounds travel through solids, liquids and gases.
Humidity also effect the speed of sound. Generally sound travel faster in denser medium, so humidity increases sound travels at faster range. For this the quality of sound changes.
Sound travels faster in summer season than in winter season. Because if the temperature increases then the speed of sound also increases with it. Means sound passes through hot air faster than it passes through cold air.
So in winter sound travels slowly due to the moisture presence.
Hence the propagation of sound in air differences during the summer and winter seasons.
(2) How does sound pollution effect Bio diversity? Explain.
Ans: – Sound/Noise pollution can be effect on human beings, animals and plants. There are many living organisms in our bio diversity. So sound pollution effects on living organisms. Sound pollution disturbs the animals, so it can cause death of smaller animals. Sound pollution effect our biodiversity in difference forms like bursting crackers and the sound of bike and any vehicles horns etc… Its first harmful effect is loss of hearing.
(III) Multiple Choice Questions
(1) An object which moves to and fro motion from rest known as….
Ans: – b) vibration
(2) The number of vibrations produced per second is known as……
Ans: – a) Frequency
(3) The audible sound range of man is……
Ans: – b) 20-20000 Vibrations/sec
(4) The oval window has the surface area……….of the eardrum
Ans: – d) 1/20
(5) The shrillness of a sound is known as………………
Ans: – a) Pitch