In SONAR we use

Correct option is B

The correct answer is: (b) Ultrasonic waves

SONAR (Sound Navigation and Ranging) is a technology used to detect and locate objects underwater by emitting sound waves and analyzing the echoes that bounce back from the objects. It utilizes ultrasonic waves, which are sound waves with frequencies higher than the human audible range (above 20,000 Hz).

Why Ultrasonic Waves Are Used:

• High Frequency: Ultrasonic waves have short wavelengths, allowing them to detect small objects with high precision.
• Directional Propagation: These waves travel in a focused and straight path, making them ideal for underwater exploration and navigation.
• Minimal Attenuation: Ultrasonic waves can travel long distances underwater with minimal energy loss.

Applications of SONAR:

• Navigation: Used by submarines and ships to avoid underwater obstacles.
• Mapping: Helps in underwater topographical mapping.
• Fishing: Detecting fish schools in commercial fishing.
• Military: Locating enemy submarines and mines.

Additional Information:

• Infrasonic waves: These are low-frequency waves (below 20 Hz) and are not used in SONAR due to their poor resolution and long wavelengths.
• Audible sound waves: These are within the human hearing range (20 Hz to 20,000 Hz) and are not suitable for high-precision applications like SONAR.
• Radio waves: These are electromagnetic waves and are not suitable for underwater communication as they are quickly absorbed by water.