NCERT Solutions for Class 8 Science Chapter 13 Sound

NCERT Solutions for Class 8 Science Chapter 13 Sound helps you understand how vibrations create the noise we hear every day. These solutions explain why sound needs a medium like air or water to travel. By using these guides, we learn about pitch, loudness, and how our ears work to catch different types of sound waves easily.

Class 8 Science Chapter 13 Sound

You can find the best ways to answer your book questions right here. This guide makes learning about noise and music very easy. We show you how to solve every problem step-by-step so you don't get stuck.

Sound Is Produced by Vibrating Bodies

Sound starts with a vibration. When an object moves back and forth very fast, it makes a sound.

• Vibrating Strings: Instruments like the sitar use thin wires.

• Stretched Skins: Drums or the dholak use a tight surface.

• Air Columns: Flutes make sound when air moves inside them.

How Humans Create Different Sounds

We have a special part in our throat called the voice box. It's also called the larynx.

1. Vocal Cords: Two stretchy bands are pulled across the voice box.

2. Air Gap: A tiny slit lets air pass through from the lungs.

3. Vibration: When we speak, air makes the cords shake to create our voice.

Read More - NCERT Solutions for Class 8 Maths Chapter 8 Algebraic Expressions and Identities

Understanding Sound Class 8 Questions and Answers

Learning these answers helps you do great in your class tests. We explain things like how sound moves through walls or water.

Why Sound Needs a Medium

Sound is like a traveler that needs a road. It cannot move if there's nothing to carry it.

• Solids: Sound moves fastest through things like metal or wood.

• Liquids: You can hear sounds underwater too.

• Gases: This is how we hear people talking through the air.

• Vacuum: Sound can't travel in empty space where there's no air.

How We Hear Using Our Ears

Our ears are like funnels that catch sounds from around us.

• Outer Ear: The part you see collects the sound.

• Ear Canal: The sound travels down this little tube.

• Eardrum: A thin skin that vibrates when sound hits it.

• To the Brain: These vibrations turn into signals for our brain.

Useful Sound Class 8 Questions and Answers PDF

Many students look for a sound class 8 questions and answers pdf to study offline. It's helpful to have a list of all the important terms in one place.

Defining Amplitude and Frequency

These words tell us how a sound feels and sounds to us.

• Amplitude: This tells us how loud a sound is. Large vibrations make loud sounds.

• Frequency: This is the number of shakes per second. It's measured in Hertz (Hz).

• Time Period: The time it takes for one full vibration to happen.

Difference Between Pitch and Loudness

We can tell voices apart because of these two things.

• High Pitch: A bird chirping or a whistle.

• Low Pitch: A drum beating or a man’s voice.

Learning Sound Class 8 Questions and Answers Extra

Sometimes the book questions aren't enough. We need sound class 8 questions and answers extra to understand the tricky parts of the chapter.

What are Audible and Inaudible Sounds?

Not every sound can be heard by us. Our ears have a limit.

• Audible Range: Humans hear between 20 Hz and 20,000 Hz.

• Inaudible Sound: Sounds below 20 Hz or above 20,000 Hz are silent to us.

• Animal Hearing: Dogs can hear much higher sounds than humans can.

Music Versus Noise

We like some sounds, but others can be very annoying.

• Music: Sounds that feel pleasant and nice to the ear.

• Noise: Sounds that are loud, harsh, and unwanted.

• Can Music become Noise? Yes, if you play it too loudly, it becomes noise.

Read More - NCERT Solutions for Class 8 Maths Chapter 1 Rational Numbers

Facts for Sound Class 8 Questions and Answers NCERT

The sound class 8 questions and answers NCERT focus a lot on how we can stay healthy around loud noises. Noise pollution is a real problem today.

Causes of Noise Pollution

Many things around us make too much noise.

• Moving cars, buses, and loud horns on the road.

• Explosions from firecrackers during festivals.

• Machines in big factories and construction sites.

• Loudspeakers and high-volume TV at home.

How to Reduce Noise Pollution

We must try to keep our world quiet and peaceful.

• Plant Trees: Trees along roads help soak up the noise.

• Low Volume: Keep your TV and music at a soft level.

• Silencers: Engines should have parts that make them quiet.

• Move Factories: Big noisy buildings should be far from homes.

Health Risks of Too Much Noise

Loud noise doesn't just hurt your ears; it affects your body too.

1. Lack of Sleep: It’s hard to rest in a noisy place.

2. Stress: Loud sounds make people feel worried or angry.

3. Headaches: Constant noise can cause pain in the head.

4. Hearing Loss: Very loud sounds can damage your ears forever.

Why Light is Faster than Sound

During a storm, you see lightning before you hear the thunder.

• Speed: Light travels much faster than sound does.

• Distance: Both happen at the same time, but light wins the race to your eyes.

Important Numerical Practice

You might see math problems about pendulums in your exam.

• Frequency Formula: Number of vibrations divided by time.

• Example: If a bell rings 50 times in 5 seconds, its frequency is 10 Hz.

• Time Period: 1 divided by the frequency.

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