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प्रश्न
What is Galton’s whistle? To what use is it put?
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उत्तर
A special whistle that can produce ultra sound, not heard by humans, is called Galton’s whistle.
It is used to train dogs because they can hear ultrasounds up to a frequency of 40000 hertz.
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संबंधित प्रश्न
The sketches I to IV in following Figure show sound waves, all formed in the same time interval.
 |
 |
| I | II |
 |
 |
| III | IV |
Which diagram shows
- a note from a musical instrument
- a soft (or feeble) note,
- a bass (low frequency) note.
Which has the higher frequency - ultrasonic sound or infrasonic sound?
Complete the following sentences:
An average person can hear sound of frequencies in the range ______ to _________.
Complete the following sentence:
Infrasonic sound is of frequency ______________.
Complete the following sentence:
Elephants produce ____________sound.
Name three animals which can hear ultrasonic vibrations.
Ultraviolet radiation has a wavelength of 300Å. If the velocity of the electromagnetic wave is 3 × 108 ms-1. Calculate:
- frequency
- time period.
Does SONAR make use of infrasonic sound?
What are infrasonic and ultrasonic sounds?
Is the energy carried by the ultrasound very high or very low?
