Which of the following kinds of waves is/are audible? 1. Infrasonic waves 2. Ultrasonic waves Choose the correct code.
Neither 1 nor 2
Understanding Audible, Infrasonic, and Ultrasonic Waves
Sound travels in waves, and these waves have different frequencies. The human ear can only detect a specific range of sound frequencies. This range is known as the audible range.
What are Audible Waves?
Audible waves are sound waves that the average human ear can perceive. The typical frequency range for human hearing is from approximately 20 Hertz (Hz) to 20,000 Hertz (20 kHz).
- Waves with frequencies within this 20 Hz to 20,000 Hz range are audible.
- Waves with frequencies outside this range are generally not audible to humans.
Analyzing Infrasonic Waves
Infrasonic waves are sound waves with frequencies below the typical human hearing range.
- Their frequencies are generally less than 20 Hz.
- Examples of sources include earthquakes, volcanoes, and large weather systems.
- Humans cannot hear infrasonic waves, although some animals might be able to detect them.
Analyzing Ultrasonic Waves
Ultrasonic waves are sound waves with frequencies above the typical human hearing range.
- Their frequencies are generally greater than 20,000 Hz (20 kHz).
- Examples of uses include medical imaging (ultrasound), sonar, and pest control.
- Humans cannot hear ultrasonic waves. Animals like bats and dolphins use ultrasound for navigation (echolocation).
Conclusion on Audibility
Based on the definitions:
- Infrasonic waves (below 20 Hz) are not audible to humans.
- Ultrasonic waves (above 20,000 Hz) are not audible to humans.
Therefore, neither infrasonic waves nor ultrasonic waves are audible to humans.
Summary of Wave Types and Audibility
| Wave Type | Frequency Range | Audible to Humans? |
|---|---|---|
| Audible Waves | 20 Hz - 20,000 Hz | Yes |
| Infrasonic Waves | < 20 Hz | No |
| Ultrasonic Waves | > 20,000 Hz | No |
Considering the question asked which kind(s) of waves are audible among infrasonic and ultrasonic waves, the analysis shows that neither is audible.
Revision Table: Sound Wave Frequencies
| Concept | Frequency |
|---|---|
| Infrasonic | Below 20 Hz ($\text{<}20 \text{ Hz}$) |
| Audible | 20 Hz to 20,000 Hz ($20 \text{ Hz} \le f \le 20,000 \text{ Hz}$) |
| Ultrasonic | Above 20,000 Hz ($\text{>}20,000 \text{ Hz}$) |
Additional Information on Sound Waves
Sound is a mechanical wave that requires a medium (like air, water, or solids) to travel. It travels by causing vibrations in the medium. The speed of sound depends on the properties of the medium, such as its density and temperature. The frequency of a sound wave determines its pitch, and the amplitude determines its loudness.
- Frequency: Number of wave cycles per second, measured in Hertz (Hz).
- Amplitude: Maximum displacement or distance moved by a point on a vibrating body or wave measured from its equilibrium position. It relates to the intensity or loudness of the sound.
- Wavelength: The distance between successive crests or troughs of a wave. It is related to frequency and speed by the formula $\text{Speed} = \text{Frequency} \times \text{Wavelength}$.
Different animals have different audible ranges. For example, dogs can hear higher frequencies than humans, and elephants can hear lower frequencies.
Important Questions from Intensity and Sound Level
Which one of the following cannot be the unit of frequency of a sound wave?
The flash of lightning is seen before the thunderstorm is heard. It verifies that
The loudness of sound depends upon the
The appearance of sound to a human ear is subjectively characterized by which of the following parameters?
1. Pitch
2. Loudness
3. Quality
Choose the correct code
The waves with the frequency above the audible range of human beings are called _______.
