SONAR: The word SONAR stands for Sound Navigation And Ranging. Sonar is an apparatus used to find the depth of a sea or to locate the underwater things like shoals of fish, shipwrecks and enemy submarines. It uses ultrasonic waves to measure the distance, direction and speed of underwater objects. SONAR consists of two parts:
1. a transmitter (for emitting ultrasonic waves)
2. a receiver (for detecting ultrasonic waves)
The transmitter produces and transmits ultrasonic wave. These waves travel down the sea-water towards the bottom of the sea. When the ultrasonic sound pulse strikes the bottom of the sea, it is reflected back in the form of echo aid are sensed by the detector. The detector converts the ultrasonic waves into electrical signals which are appropriately interpreted. The distance of the object that reflected the sound wave can be calculated by knowing the speed of sound wave in water and the time interval between transmission and reception of the ultrasound. |
This will give us the depth of the sea. Let the time interval between transmission and reception of ultrasound signal be ‘t’ and the speed of sound through sea-water be ‘v;. The total distance, 2d travelled by the ultrasound is, then
2d = v x t
This method is called echo-ranging.
SONAR is used determine the depth of the sea and to locate underwater hills, valleys, submarine, ice-bergs, sunken ship, etc.
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Right Option : A | |||||||||||||||
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A sonar device on a submarine send out a signal and receives an echo 5 seconds later. Calculate the speed of sound in water, if the distance of the object from the submatine is 3625 m. | |||
Right Option : C | |||
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Which of the following are correct : (a) The word SONAR stands for Sound Navigation And Ranging. (b) Sonar is an apparatus used to find the depth of a sea. (c) SONAR consists of two parts, a transmitter (for emitting ultrasonic waves) and a receiver (for detecting ultrasonic waves). | |||
Right Option : D | |||
View Explanation |
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