Sound

Appeared in 11 of the 11 available papers.

Examined in

11 of 11 papers

Appears almost every year — treat as core

Typically worth

11.6 marks

Average per paper it appears in · 128 marks in total

Usual form

Short answer

45% of this chapter's 100 questions

Needs a diagram

25%

25 questions carry a figure — practise drawing them

Question-type distribution

Short answer45
Numerical16
Reasoning12
MCQ12
Definition6
Identification4
Diagram3
Fill in the blank2

Most frequent topics

Sound and vibrations 65Resonance 3Echo and the time of reflection 2Forced vibrations 2Loudness and amplitude 2Quality (timbre) of sound 1Echo and the speed of sound 1Quality of sound 1

Print:Questions only Questions + answers Answers only

Print chapter question bank

Showing 25 of 100 matching questions (128 marks).

25 questions

Choose the correct answers to the questions from the given options. (Do not copy the questions, write the correct answers only.)

1(x)2026

MCQEasy1 mark

Equal volumes of water are added to three cylindrical jars A, B and C of same height and radii rA, rB and rC respectively with rB < rA < rC. If you blow air into the mouth of these jars, which tube will produce the shrillest note? (a) A (b) B (c) C (d) All will produce the notes of same shrillness

2(i)

Complete the following by choosing the correct answers from the bracket:

2(i)(d)2026

Fill in the blankEasy1 mark

Quality of sound depends on its ............... [amplitude / waveform].

3(iii)(a)2026

DefinitionEasy1 mark

Define natural vibrations.

3(iii)(b)2026

Short answerEasy1 mark

How is this vibration different from damped vibrations in terms of their amplitudes?

7(ii)(a)2026

IdentificationEasy1 mark

One end of a plastic foot ruler is held tightly at the edge of a table and the other end is plucked. Name the vibrations produced in the ruler.

7(ii)(b)2026

Short answerEasy2 marks

Now the ruler is pushed inside partially and plucked again from its free end. State with a reason whether the frequency of vibration increases or decreases.

7(iii)(a)

Two persons A and B are standing in front of a cliff in the same line 170 m apart as shown in the diagram. Person B fires the gun and hears the echo in 3 s. Then the person A standing in front of the person B fires the gun. (Speed of sound in air is 340 m s-1)

7(iii)(a)

Calculate:

7(iii)(a)(1)2026

NumericalModerate1.5 marks

Calculate the distance of the person B from the cliff.

7(iii)(a)(2)2026

NumericalModerate1.5 marks

Calculate the minimum time in which B hears the gunshot fired by A.

7(iii)

Fill in the blank.

7(iii)(b)2026

Fill in the blankEasy1 mark

The echo is softer (less loud) than the original sound due to the decrease in ............... [amplitude / frequency] of the wave.

Choose the correct answers to the questions from the given options. (Do not copy the questions, write the correct answers only.)

1(xi)2025

MCQEasy1 mark

Assertion (A) : As the level of water in a tall measuring cylinder kept under running tap rises, the pitch of sound gradually increases. Reason (R) : Frequency of sound is inversely proportional to the length of the water column. (a) Both (A) and (R) are true and (R) is correct explanation of (A). (b) Both (A) and (R) are true and (R) is not the correct explanation of (A). (c) (A) is true but (R) is false. (d) (A) is false but (R) is true.

2(iii)

The displacement–time graph of a sound wave produced by a vibrating wire is shown below.

2(iii)(a)2025

Short answerEasy1 mark

How will you adjust the tension in the wire, to reduce the length of PR?

2(iii)(b)2025

Short answerEasy1 mark

Which characteristic of sound is affected by the reduction in the length of PR?

7(ii)2025

NumericalModerate3 marks

A submarine in the sea, sends ultrasonic ping and a stopwatch is started simultaneously. The stopwatch stops on receiving the reflected wave from an obstacle and reads 1 minute 40 seconds. Calculate the distance of the obstacle from the submarine (Speed of sound in water 1500 ms-1)

7(iii)

The diagrams given below show two sound boxes A and B with wires of same length (l) and tension (10 kgf) but different cross-sectional areas. Simultaneously, vibrating tuning forks of frequency 300 Hz are placed on the boxes A and B. The paper rider falls off in case of B but not in case of A.

7(iii)(a)2025

IdentificationEasy2 marks

Name and explain the phenomenon responsible for the falling off of the paper rider in B.

7(iii)(b)2025

ReasoningModerate2 marks

The wire A resonates with a tuning fork of frequency ‘f’. Is ‘f’ greater than, less than or equal to 300 Hz? Justify your answer.

Choose the correct answers to the questions from the given options. (Do not copy the questions, write the correct answers only.)

1(vi)2024

MCQEasy1 mark

When the stem of vibrating tuning fork is pressed on a table, the tabletop starts vibrating. These vibrations are definitely an example of: (a) resonance (b) natural vibrations (c) forced vibrations (d) damped vibrations

2(vii)2024

ReasoningModerate2 marks

Rohan conducted experiments on echo in different media. He observed that a minimum distance of ‘x’ metres is required for the echo to be heard in oxygen and ‘y’ metres in benzene. Compare ‘x’ and ‘y’. Justify your answer. Speed of sound in oxygen: 340 m s⁻¹ Speed of sound in benzene: 200 m s⁻¹

7(i)(a)2024

IdentificationEasy1 mark

Name the waves used in SONAR.

7(i)(b)2024

NumericalModerate2 marks

In the above diagram Lata stands between two cliffs and claps her hands. Determine the time taken by her to hear the first echo. Speed of sound in air = 320 m s⁻¹.

7(iii)

In the given diagram, a vibrating tuning fork is kept near the mouth of a burette filled with water. The length of the air column is adjusted by opening the tap of the burette. At a length of 5 cm of the air column, a loud sound is heard.