Advertisements
Advertisements
प्रश्न
What is ultrasound ? What is the difference between ordinary sound and ultrasound ?
Advertisements
उत्तर
Ultrasound waves are high-frequency sound waves. Due to higher frequency, they can penetrate into matter to a large extent.
We can differentiate between ordinary and ultrasonic waves as :
| Audible sound waves | Ultrasound waves |
| They have a frequency range of 20 Hz–20,000 Hz | They have frequencies above 20,000 Hz |
| These sounds are audible to human ears. | These sounds are inaudible to human ears. |
APPEARS IN
संबंधित प्रश्न
What is the audible range of the average human ear?
Fill in the blanks with suitable words.
A sound wave consists of places of higher pressure called ................. and places of................pressure called.................
Can we hear (a) infrasonic waves (b) ultrasonic waves ?
Choose the infrasonic waves and ultrasonic waves from the following frequencies :
(i) 10,000 Hz
(ii) 30,000 Hz
(iii) 18 Hz
(iv) 50,000 Hz
(v) 10 Hz
Which of the following sound frequencies cannot be heard by a human ear ?
(i) 10 Hz
(ii) 100 Hz
(iii) 10,000 Hz
(iv) 15 Hz
(v) 40,000 Hz
What are infrasonic waves ? Name two animals which produce infrasonic waves.
What are ultrasonic waves ? Name two animals which can produce ultrasonic waves.
The audible range of frequencies of an average human ear is from 20 Hz to 20 kHz. Calculate the corresponding wavelengths. (Speed of sound in air is 344 ms–1)
Which of the above two graphs (a) and (b) (Fig.12.3) representing the human voice is likely to be the male voice? Give a reason for your answer.
A girl is sitting in the middle of a park of dimension 12 m × 12 m. On the left side of it, there is a building adjoining the park and on the right side of the park, there is a road adjoining the park. A sound is produced on the road by a cracker. Is it possible for the girl to hear the echo of this sound? Explain your answer.
