Sound and Waves

Learn wave properties and sound behavior used in objective questions.

Level

Core

Study Time

16 min

Exam Relevance

Medium

Core concepts

Wave terms: amplitude, frequency, wavelength, time period.
Relation: v = fλ.
Nature of sound waves and propagation medium.
Reflection of sound and echo conditions.

Fast-solving steps

List given data in symbols.
Convert units (Hz, m, s) first.
Apply v = fλ only after unit correction.

Common mistakes

Confusing loudness with pitch.
Mixing frequency and time period.

Chapter-end mini quiz

5 quick questions from the question bank.

Question 1

Which one among the following is true for the speed of sound in a given medium?

Speed of sound remains same at all frequenciesSpeed of sound is faster at higher frequenciesSpeed of sound is slower at higher frequenciesSpeed of sound is slower at higher wavelengths

Question 2

SONAR is a device that is used to measure the distance of underwater objects by a ship. Which of the following types of waves does it use for this purpose?

Infrasonic wavesSound waves in audible range for human beingsUltrasonic wavesAll of the above

Question 3

Which one of the following frequency ranges is sensitive to human ears?

0 - 200 Hz20 - 20,000 Hz200 - 20,000 Hz only2,000 - 20,000 Hz only

Question 4

Which one of the following statements is not correct?

Ultrasonic waves cannot get reflected, refracted or absorbed.Ultrasonic waves are used to detect the presence of defects like cracks, porosity, etc. in the internal structure of common structure materials.Ultrasonic waves can be used for making holes in very hard materials like diamond.Ultrasonic waves cannot travel through vacuum.

Question 5

When the pitch of sound increases, which one of the following increases?

IntensityLoudnessWavelengthFrequency

Source Base

NCERT wave motion and sound fundamentals
CBSE numerical sets on frequency, wavelength and speed

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