Are these practice questions for Sound Waves: Characteristics and Applications based on the CBSE pattern?

Yes. Every practice question is modeled on the CBSE Class 9 Science exam pattern — including MCQs, assertion-reason questions, and short-answer formats that frequently appear in CBSE papers.

Are the practice questions for Sound Waves: Characteristics and Applications free?

Yes. Every chapter includes free practice questions for Class 9 students to get you started.

What types of questions are included?

The practice set for Sound Waves: Characteristics and Applications mainly includes MCQs and CBSE-style short-answer questions, with instant feedback on each answer. For full-length textbook practice, use the NCERT Solutions page.

Are the practice questions suitable for board exam preparation?

Yes. The questions test the same concepts and depth that CBSE asks in board exams. After finishing, also solve the NCERT and NCERT Exemplar exercises for Sound Waves: Characteristics and Applications for full coverage.

How many practice questions are there for Sound Waves: Characteristics and Applications?

The number scales with chapter length and concept density. Each chapter typically has 15-50 practice questions across MCQ and short-answer formats.

Sound Waves: Characteristics and Applications Class 9 Science Practice Questions with Answers

easy

Examine why an alarm clock ringing inside a sealed bell jar becomes inaudible as the air is pumped out, even though the hammer can still be seen striking the bell.

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easy

Name the three states of matter through which sound can propagate.

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easy

Two friends are standing at opposite ends of a long steel railway track. One friend strikes the track with a hammer. The other friend, with her ear to the track, hears two sounds: a sharp sound through the track first, followed by a fainter sound through the air. Propose a reason for this phenomenon and justify it using the properties of sound propagation in different media.

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easy

A tuning fork has a marked frequency of

256 \text{ Hz}

. Calculate the number of complete oscillations its prongs will make in one minute.

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easy

Formulate a general rule that describes the relationship between the time delay of a returning echo and an object's distance from the sound source.

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easy

Two sound waves, A and B, are produced in the same medium. Wave A has an amplitude of

5

units and a frequency of

200 \text{ Hz}

. Wave B has an amplitude of

10

units and a frequency of

400 \text{ Hz}

. Evaluate which wave would be perceived as louder and which would have a higher pitch. Justify your answer.

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easy

Name the technique used by bats and in naval submarines (sonar) to locate objects.

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easy

Analyze how placing rice grains on a drum and then striking a nearby drum demonstrates that sound waves transfer energy without transferring matter.

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easy

Define vibration in the context of sound production.

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easy

Recall the audible frequency range for a typical human.

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easy

Evaluate the claim that a drummer can change the pitch of a drum by tightening the drum skin. Justify your conclusion based on the physics of vibrations.

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easy

Examine the relationship between the frequency of a sound wave and its perceived pitch. How would the pitch of a whistle compare to the pitch of a drum?

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easy

Critique the scientific accuracy of a movie scene depicting a massive explosion of a spaceship in the vacuum of outer space, where the audience hears a loud booming sound simultaneously with seeing the explosion. Justify your critique using two distinct principles of sound waves.

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easy

Define pitch and name the physical property of a sound wave it is primarily related to.

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medium

Explain the difference between an echo and reverberation.

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medium

A bat emits an ultrasonic sound with a frequency of

50 \text{ kHz}

. If the speed of sound in air is

340 \text{ m/s}

, calculate the wavelength of this sound.

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medium

A ship's SONAR sends out an ultrasonic signal to determine the ocean depth. The echo is detected

4

seconds later. Create a problem to find the ocean depth, assuming a speed of sound in seawater, and then solve it. The speed you assume must be a realistic value.

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medium

Contrast the sound produced when you pluck a tightly stretched thin guitar string versus a loosely stretched thick bass string. Analyze the expected differences in their frequency and pitch.

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medium

A tuning fork produces a sound wave of frequency

256 \text{ Hz}

. Calculate the time period of the vibration.

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medium

Explain the terms wavelength, frequency, and amplitude of a sound wave and state their SI units.

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medium

A car's reverse parking sensor emits an ultrasonic pulse when it is

1.7 \text{ m}

away from a wall. Calculate the time elapsed between the emission of the pulse and the detection of its echo. The speed of sound in air is

340 \text{ m/s}

.

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medium

A submarine's sonar system sends out an ultrasonic pulse and receives the echo from the seabed 1.2 seconds later. If the speed of sound in seawater is

1530 \text{ m/s}

, calculate the depth of the sea at that location.

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medium

Compare a sound wave and a light wave based on the direction of particle vibration relative to wave propagation and the requirement of a medium.

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medium

In a science fiction movie, a spaceship explodes in the vacuum of space. The scene shows a bright flash of light and simultaneously a loud booming sound. Analyze this depiction and explain the two major scientific errors related to the propagation of sound and light.

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medium

Two sound waves, A and B, are represented on identical graphs of density versus distance. Wave A completes 2 full cycles over a distance of 8 cm, with a maximum density change of 5 units. Wave B completes 4 full cycles over the same distance, with a maximum density change of 3 units. Compare the two waves in terms of their wavelength and amplitude.

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medium

A musician claims that by replacing a thin guitar string with a thicker one of the same material and keeping the tension and length the same, the pitch of the note produced will become lower. Evaluate this claim and justify your reasoning based on the principles of sound production.

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medium

Justify why SONAR systems, used for mapping the ocean floor, operate with ultrasound (frequencies above

20 \text{ kHz}

) rather than audible sound or infrasound.

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medium

Explain why astronauts on a spacewalk cannot hear each other speak directly, even if they are close.

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medium

A bat emits an ultrasonic pulse and receives the echo from an insect

0.02

seconds later. Propose a method to calculate the distance to the insect and then perform the calculation. Justify the formula used. Assume the speed of sound in air is

340 \text{ m/s}

.

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medium

A vibrating source produces 50 compressions that pass a point in 5 seconds. Calculate the frequency and time period of the sound wave.

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medium

Describe the terms infrasound and ultrasound, and state their frequency ranges relative to human hearing.

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medium

A sound wave has a frequency of

500 \text{ Hz}

and a wavelength of

0.7 \text{ m}

. Recall the formula relating speed, frequency, and wavelength, and calculate the speed of the sound wave.

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medium

Design a graphical representation of a sound wave with a wavelength of

4 \text{ m}

and an amplitude corresponding to a maximum density change of

2

units above the average. Label the axes, wavelength, and amplitude on your proposed graph.

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medium

Justify the assertion: The individual particles of air do not travel from a speaker to your ear, yet the sound does.

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medium

Identify the type of wave a sound wave is (longitudinal or transverse) and describe the particle motion relative to the wave's direction of propagation.

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medium

Describe what compressions and rarefactions are in a longitudinal sound wave.

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medium

Design an experiment, using common household items, to propose a method for demonstrating that sound requires a medium. Justify why your chosen setup would be effective, avoiding the use of a standard bell jar and vacuum pump.

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medium

Propose a detailed procedure for a group of students to measure the speed of sound in air using the principle of echo in a large open space. Formulate the final equation they would use to calculate the speed.

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medium

The graph of a sound wave shows that the distance covering three consecutive compressions is 8 meters. If the wave travels at a speed of

340 \text{ m/s}

, calculate its frequency.

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hard

Evaluate the acoustic design of a large, empty hall with smooth, parallel concrete walls and a high ceiling for use as a speech auditorium. Propose two specific modifications to improve its suitability and justify how each modification would enhance sound clarity.

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hard

Recall the minimum time interval required for the human brain to distinguish two sounds. Using this, calculate the minimum distance to a reflecting surface to hear a clear echo, if the speed of sound in air is

340 \text{ m/s}

.

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hard

Two friends are standing 510 m apart along a long iron railway track. One friend strikes the track with a hammer. The other friend, with her ear to the track, hears two sounds. Calculate the time interval between the two sounds. Use speed of sound in air =

340 \text{ m/s}

and in iron =

5100 \text{ m/s}

.

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hard

Critique the common simplification used in calculating the distance of a lightning strike, which assumes that light travels instantaneously. Justify whether this is a reasonable simplification by calculating the time it takes for light to travel

3.4 \text{ km}

and comparing it to the time for sound. Use speed of sound

v_{sound} = 340 \text{ m/s}

and speed of light

c = 3 \times 10^8 \text{ m/s}

.

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hard

Explain why the sound of a distant thunder is heard after the flash of lightning is seen. Also, summarize how the speed of sound generally compares in solids, liquids, and gases.

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hard

An observer stands in a canyon and claps her hands. She hears the first echo after

1.5 \text{ s}

. Calculate the distance to the canyon wall. Then, analyze how the time to hear the echo would change if the canyon were filled with water, where the speed of sound is approximately 4.4 times faster than in air. Assume the speed of sound in air is

340 \text{ m/s}

.

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Sound Waves: Characteristics and ApplicationsClass 9 Science Practice Questions