Consider the following statements regarding the nature of sound waves: 1. Sound waves in air are longitudinal waves. 2. In a longitudinal wave, particles move perpendicular to the direction of wave propagation. 3. Light waves are examples of longitudinal waves. Which of the statements given above is/are correct?

Correct Option The correct option is (a). Explanation Waves are disturbances that transport energy. Based on the direction of particle oscillation relative to the direction of wave propagation, mechanical waves are classified into longitudinal and transverse waves. Statement-wise Analysis - Statement 1 is Correct: Sound waves in air are longitudinal waves. They propagate through the medium as a series of compressions (high pressure) and rarefactions (low pressure). - Statement 2 is Incorrect: In a longitudinal wave, the particles of the medium oscillate parallel to the direction of wave propagation. It is in transverse waves that particles oscillate perpendicular to the direction of propagation. - Statement 3 is Incorrect: Light waves are electromagnetic waves and are transverse in nature. In light waves, the electric and magnetic fields oscillate perpendicular to the direction of the wave's travel. Key Takeaway: Sound waves in fluids are longitudinal (parallel oscillation), whereas light waves are transverse (perpendicular oscillation).

Consider the following statements regarding the nature of sound waves: 1. Sound… - NCERT Class 9 Science MCQ

NCERT Class 9 Science — Chapter 5: Sound

mcqmedium

Consider the following statements regarding the nature of sound waves:

Sound waves in air are longitudinal waves.
In a longitudinal wave, particles move perpendicular to the direction of wave propagation.
Light waves are examples of longitudinal waves.

Which of the statements given above is/are correct?

NCERT textbook question

From NCERT Science - class 9 · Page 3

Options

A1 only
B2 only
C1 and 3 only
D1, 2 and 3

Did you get this right?

Solution

Correct Option

The correct option is (a).

Explanation

Waves are disturbances that transport energy. Based on the direction of particle oscillation relative to the direction of wave propagation, mechanical waves are classified into longitudinal and transverse waves.

Statement-wise Analysis

Statement 1 is Correct: Sound waves in air are longitudinal waves. They propagate through the medium as a series of compressions (high pressure) and rarefactions (low pressure).
Statement 2 is Incorrect: In a longitudinal wave, the particles of the medium oscillate parallel to the direction of wave propagation. It is in transverse waves that particles oscillate perpendicular to the direction of propagation.
Statement 3 is Incorrect: Light waves are electromagnetic waves and are transverse in nature. In light waves, the electric and magnetic fields oscillate perpendicular to the direction of the wave's travel.

Key Takeaway: Sound waves in fluids are longitudinal (parallel oscillation), whereas light waves are transverse (perpendicular oscillation).

Your note

More from Chapter 5: Sound

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