MCQ Detailed View

Sonar (Sound Navigation and Ranging) is a technique used to detect and locate objects underwater by sending out sound waves and analyzing their reflection (echo). While radar uses radio waves for detection in the atmosphere or space, sonar relies on ultrasonic sound waves.       ✅ How Sonar Works:

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  Sonar devices emit ultrasonic waves, which are sound waves with frequencies above the human hearing range (greater than 20,000 Hz).

  
  


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  These waves travel through water, strike an object (like a submarine or the seabed), and reflect back as an echo.

  
  


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  By measuring the time taken for the echo to return, the system calculates the distance and position of the object.

  
  

✅ Why Ultrasonic Waves Are Used:

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  Radio waves do not travel well in water, as they are absorbed quickly.

  
  


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  Sound waves can travel long distances in water because water is a better conductor for sound.

  
  


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  Ultrasonic waves provide high-frequency precision, allowing accurate detection and mapping of underwater objects.

  
  

✅ Applications of Sonar:

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  Navigation for submarines and ships

  
  


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  Measuring ocean depth (echo-sounding)

  
  


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  Locating underwater hazards, wreckages, and marine life

  
  


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  Military applications for detecting enemy submarines or torpedoes.

  
  

❌ Incorrect Options:

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  Red waves & Infrared waves: These are light waves and cannot travel well in water.

  
  


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  Supersonic: Refers to objects moving faster than the speed of sound, not a type of wave.

  
  

✅ Final Answer:

Sonar uses ultrasonic waves for underwater detection, making Option 3 correct.