Sound Class 8 Worksheet with Answers & Notes

Production and Propagation of Sound

Subtopic

Production and Propagation of Sound under Sound for Grade 8 CBSE.

Preview questions (no answers)

1.
$If you scratch one end of a long wooden log, your friend at the other end can hear it. This proves sound travels through:$
A. $Gases$
B. $Liquids$
C. $Solids$
D. $Vacuum$
2.
$The sound of a school bell travels to our ears through the:$
A. $Water$
B. $Wood$
C. $Air$
D. $Iron$
3.
$In a toy telephone made of two paper cups and a string, sound travels through the:$
A. $Air inside the cups$
B. $String$
C. $Empty space$
D. $Light$
4.
$When we hear a sound, it means some object must be:$
A. $In a vacuum$
B. $Stationary$
C. $Vibrating$
D. $Heated$
5.
$f$
A. $f = T$
B. $f = 1/T$
C. $f = T^2$
D. $f = 2T$
6.
$When sound travels through a medium, the particles of the medium:$
A. $Move along with the sound to the listener$
B. $Vibrate about their mean positions$
C. $Stop vibrating$
D. $Move in the opposite direction of sound$
7.
$Which of the following is a stringed instrument?$
A. $Trumpet$
B. $Tabla$
C. $Violin$
D. $Flute$
8.
$A sound wave is represented by a graph of displacement versus time. If the distance between two consecutive peaks (crests) on the graph is reduced by half, how does it affect the perceived sound?$
A. $The loudness is doubled.$
B. $The pitch is doubled.$
C. $The pitch is halved.$
D. $The loudness is reduced by four times.$
9.
$A person is swimming underwater in a pool. If a bell is rung at the surface, will the swimmer hear it? Why or why not?$
A. $No, sound cannot travel from air into water.$
B. $Yes, because sound travels faster and efficiently through water than air.$
C. $No, because the swimmer's ears are filled with water, blocking vibrations.$
D. $Yes, but the sound will be very distorted because water absorbs all high frequencies.$
10.
$50$
A. $50$
B. $100$
C. $25$
D. $200$

Download the worksheet for Sound - Production and Propagation of Sound to practice offline. It includes additional chapter-level practice questions.

Sound Produced by Humans: Larynx

Subtopic

Sound Produced by Humans: Larynx under Sound for Grade 8 CBSE.

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1.
$What type of sound is produced when the vocal cords are loose and thick?$
A. $High pitch$
B. $Low pitch$
C. $Screaming$
D. $No sound$
2.
$Which part of the body acts like the 'bellows' that provide the air stream for speech?$
A. $The stomach$
B. $The lungs$
C. $The throat$
D. $The mouth$
3.
$If you touch your larynx while humming, the sensation you feel is due to:$
A. $Air pressure$
B. $Vibration$
C. $Muscle growth$
D. $Heat transfer$
4.
$The pitch of the human voice is most directly related to the ________ of the vocal cords.$
A. $Color$
B. $Temperature$
C. $Tension$
D. $Volume$
5.
$Which of these is the correct path of air during speech production?$
A. $Mouth -> Lungs -> Larynx$
B. $Lungs -> Larynx -> Mouth/Nose$
C. $Larynx -> Lungs -> Mouth$
D. $Trachea -> Lungs -> Larynx$
6.
$When a person whispers, how does the behavior of the vocal cords change compared to normal speech?$
A. $They vibrate much faster.$
B. $They do not vibrate in the same way; air passes through with less vibration.$
C. $They close the slit completely.$
D. $They become thicker and looser.$
7.
$What determines whether a voice is 'hoarse' or 'clear'?$
A. $The length of the windpipe$
B. $The condition and vibration of the vocal cords$
C. $The size of the lungs$
D. $The temperature of the air$
8.
$Why does sound stop immediately when we stop expelling air from our lungs, even if our vocal cords are still in the 'speech' position?$
A. $Because the brain sends a signal to stop the vibration$
B. $Because there is no longer a force (moving air) to cause the vocal cords to oscillate$
C. $Because the vocal cords automatically relax when air flow stops$
D. $Because the sound waves are absorbed by the trachea$
9.
$Which of these comparisons between a man's and a woman's larynx is scientifically accurate?$
A. $A man's larynx is usually smaller and positioned higher$
B. $5\text{ mm}$
C. $A man's vocal cords vibrate at a higher frequency$
D. $There is no anatomical difference between the two$
10.
$What is the primary function of the muscles surrounding the larynx?$
A. $To push food into the stomach$
B. $To adjust the tension and position of the vocal cords$
C. $To help the lungs expand during breathing$
D. $To protect the neck from external injury$

Download the worksheet for Sound - Sound Produced by Humans: Larynx to practice offline. It includes additional chapter-level practice questions.

Characteristics of Sound: Amplitude and Frequency

Subtopic

Characteristics of Sound: Amplitude and Frequency under Sound for Grade 8 CBSE.

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Preview questions (no answers)

1.
$To change a feeble sound to a loud sound, we must increase its:$
A. $Frequency$
B. $Amplitude$
C. $Pitch$
D. $Speed$
2.
$0.02$
A. $20 Hz$
B. $50 Hz$
C. $100 Hz$
D. $200 Hz$
3.
$A sound with a high pitch is often described as being:$
A. $Dull$
B. $Hoarse$
C. $Shrill$
D. $Faint$
4.
$When we strike a drum harder, we increase the ________ of the vibrations.$
A. $Frequency$
B. $Amplitude$
C. $Time period$
D. $Pitch$
5.
$A sound wave has a high amplitude and a low frequency. How would you describe this sound?$
A. $Faint and low-pitched$
B. $Loud and low-pitched$
C. $Faint and high-pitched$
D. $Loud and high-pitched$
6.
$0.01$
A. $10\ Hz$
B. $100\ Hz$
C. $1\ Hz$
D. $0.1\ Hz$
7.
$What happens to the frequency of sound produced by a flute when more holes are closed?$
A. $It increases$
B. $It decreases$
C. $It remains the same$
D. $Loudness increases$
8.
$0.2$
A. $5\ Hz$
B. $2.5\ Hz$
C. $0.4\ Hz$
D. $10\ Hz$
9.
$200\ Hz$
A. $3$
B. $9$
C. $9$
D. $6$
10.
$500$
A. $2500\ kHz$
B. $2.5\ kHz$
C. $0.5\ kHz$
D. $5\ kHz$

Download the worksheet for Sound - Characteristics of Sound: Amplitude and Frequency to practice offline. It includes additional chapter-level practice questions.

Audible and Inaudible Sounds

Subtopic

Audible and Inaudible Sounds under Sound for Grade 8 CBSE.

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Preview questions (no answers)

1.
$A child can often hear slightly higher frequencies than an elderly person, but the standard lower limit for humans is generally considered to be:$
A. $200\text{ Hz}$
B. $20\text{ Hz}$
C. $2\text{ Hz}$
D. $20,000\text{ Hz}$
2.
$Which of the following sounds is inaudible due to having a frequency that is too low?$
A. $Ultrasonic sound$
B. $Audible sound$
C. $Infrasonic sound$
D. $Loud sound$
3.
$5\text{ Hz}$
A. $1$
B. $5$
C. $20$
D. $50$
4.
$Sound frequencies higher than the range of human hearing are used in:$
A. $Simple pendulums$
B. $Drum sets$
C. $Industrial cleaning of small parts$
D. $Violins$
5.
$What is the primary difference between audible and inaudible sounds for a human?$
A. $Audible sounds have more energy than inaudible sounds.$
B. $Inaudible sounds do not travel through air.$
C. $20\text{ Hz} - 20,000\text{ Hz}$
D. $Audible sounds are always pleasant, while inaudible sounds are noise.$
6.
$150\text{ Hz}$
A. $Audible$
B. $Infrasonic$
C. $Ultrasonic$
D. $Subsonic$
7.
$Which frequency is exactly at the lower threshold of human hearing?$
A. $10\text{ Hz}$
B. $20\text{ Hz}$
C. $200\text{ Hz}$
D. $2000\text{ Hz}$
8.
$25,000$
A. $250$
B. $2,500$
C. $25,000$
D. $2.5$
9.
$30,000$
A. $500$
B. $30,000$
C. $50$
D. $300$
10.
$Identify the sound category that travels through the earth's crust during a volcanic eruption before it is heard by humans.$
A. $Audible sound$
B. $Ultrasonic sound$
C. $Infrasonic sound$
D. $Light waves$

Download the worksheet for Sound - Audible and Inaudible Sounds to practice offline. It includes additional chapter-level practice questions.

Noise Pollution and Control Measures

Subtopic

Noise Pollution and Control Measures under Sound for Grade 8 CBSE.

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1.
$If a neighbor is playing loud music late at night, what is the most responsible action to take?$
A. $Play your own music even louder$
B. $Politely request them to lower the volume or report to local authorities if it continues$
C. $Break their music system$
D. $Do nothing and stay awake all night$
2.
$Which of these is a non-technical way to reduce noise pollution in a community?$
A. $Installing expensive sound walls$
B. $Creating awareness about the harmful effects of noise$
C. $Buying everyone noise-canceling headphones$
D. $Banning all electronics$
3.
$How can we help people with hearing impairment caused by noise?$
A. $By shouting at them$
B. $By providing them with hearing aids$
C. $By ignoring them$
D. $By playing louder music$
4.
$Which type of surface is best at reflecting sound, thereby potentially increasing noise in a room?$
A. $Soft sponge$
B. $Hard and smooth surfaces like concrete walls$
C. $Thick velvet cloth$
D. $Woolen blankets$
5.
$Which of the following combinations represents only sources of noise pollution?$
A. $Flute, Violin, Piano$
B. $Pressure horn, Kitchen mixer, Loudspeakers$
C. $Bird chirping, Rustling leaves, Soft breeze$
D. $Clock ticking, Whispering, Breathing$
6.
$Why is it important to keep the volume of earphones low?$
A. $To save the battery of the phone$
B. $To prevent permanent hearing loss$
C. $To increase the bass of the music$
D. $To make the earphones last longer$
7.
$Which part of the human ear is most susceptible to damage from loud noise?$
A. $Pinna$
B. $Ear canal$
C. $Eardrum$
D. $Outer ear$
8.
$A 'Sonic Boom' is an extreme form of noise pollution caused by:$
A. $A very large explosion on the ground.$
B. $An aircraft traveling faster than the speed of sound.$
C. $A massive thunderstorm.$
D. $A high-power loudspeaker system.$
9.
$In the study of acoustics, what does the 'Coincidence Effect' refer to in a noise-reducing panel?$
A. $When two people talk at the same time.$
B. $When the wavelength of the incident sound matches the wavelength of the bending waves in the panel, reducing its effectiveness.$
C. $When the noise is blocked perfectly by the panel.$
D. $When the sound and light reach the panel at the same time.$
10.
$100\text{ meters}$
A. $To prevent sound from interfering with sensitive medical equipment only.$
B. $To ensure a recovery-friendly environment for patients and a focused environment for students.$
C. $Because sound travels faster near hospitals.$
D. $To prevent oxygen from vibrating too much.$

Download the worksheet for Sound - Noise Pollution and Control Measures to practice offline. It includes additional chapter-level practice questions.

Sound

Production and Propagation of Sound

❓Preview questions (no answers)

Sound Produced by Humans: Larynx

❓Preview questions (no answers)

Characteristics of Sound: Amplitude and Frequency

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Audible and Inaudible Sounds

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Noise Pollution and Control Measures

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