With reference to the audible range of sound, consider the following statements: 1. The audible range for an average human is 200 Hz to 200,000 Hz. 2. Sounds with frequencies below 20 Hz are called infrasound. 3. Rhinoceroses communicate using infrasound. Which of the statements given above are correct?

Correct Option The correct option is (c) 2 and 3 only. Explanation Sound waves are classified based on their frequency relative to the human hearing capability. The frequency of sound is measured in Hertz (Hz). Sounds are categorized into infrasonic, audible, and ultrasonic ranges. Statement-wise Analysis - Statement 1 is Incorrect: The audible range of sound for an average human being extends from 20 Hz to 20,000 Hz (20 kHz). The statement incorrectly cites the range as 200 Hz to 200,000 Hz. Children under the age of five and some animals, such as dogs, can hear up to 25 kHz, but the standard human range is 20 Hz–20 kHz. - Statement 2 is Correct: Sounds with frequencies below 20 Hz are technically termed infrasonic sound or infrasound. These frequencies are below the lower limit of human audibility. - Statement 3 is Correct: Rhinoceroses communicate using infrasound with frequencies as low as 5 Hz. Other animals, such as whales and elephants, also produce and communicate via sound in the infrasound range. It is observed that some animals get disturbed before earthquakes because earthquakes produce low-frequency infrasound before the main shock waves begin. Key Takeaway Sound Frequency Classification: - Infrasound: Frequency 20,000 Hz (e.g., Bats, Dolphins, Rats).

With reference to the audible range of… - NCERT Class 9 Science MCQ

NCERT Class 9 Science — Chapter 5: Sound

mcqmedium

With reference to the audible range of sound, consider the following statements:

The audible range for an average human is 200 Hz to 200,000 Hz.
Sounds with frequencies below 20 Hz are called infrasound.
Rhinoceroses communicate using infrasound.

Which of the statements given above are correct?

NCERT textbook question

From NCERT Science - class 9 · Page 9

Options

A1 and 2 only
B2 only
C2 and 3 only
D1, 2 and 3

Did you get this right?

Solution

Correct Option

The correct option is (c) 2 and 3 only.

Explanation

Sound waves are classified based on their frequency relative to the human hearing capability. The frequency of sound is measured in Hertz (Hz). Sounds are categorized into infrasonic, audible, and ultrasonic ranges.

Statement-wise Analysis

Statement 1 is Incorrect: The audible range of sound for an average human being extends from 20 Hz to 20,000 Hz (20 kHz). The statement incorrectly cites the range as 200 Hz to 200,000 Hz. Children under the age of five and some animals, such as dogs, can hear up to 25 kHz, but the standard human range is 20 Hz–20 kHz.
Statement 2 is Correct: Sounds with frequencies below 20 Hz are technically termed infrasonic sound or infrasound. These frequencies are below the lower limit of human audibility.
Statement 3 is Correct: Rhinoceroses communicate using infrasound with frequencies as low as 5 Hz. Other animals, such as whales and elephants, also produce and communicate via sound in the infrasound range. It is observed that some animals get disturbed before earthquakes because earthquakes produce low-frequency infrasound before the main shock waves begin.

Key Takeaway

Sound Frequency Classification:

Infrasound: Frequency < 20 Hz (e.g., Rhinoceros, Whales, Elephants).
Audible Sound: Frequency 20 Hz – 20,000 Hz (Humans).
Ultrasound: Frequency > 20,000 Hz (e.g., Bats, Dolphins, Rats).

Your note

More from Chapter 5: Sound

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