Which of the following characteristics of a wave is used in the measurement of the depth of the Sea?

Analysis

The question asks for the specific wave property utilized in sonar technology (echo sounding) to determine the depth of the ocean.

Concept Explanation

To measure the depth of the sea, scientists use a technique called Echo Sounding. This process involves sending a pulse of sound (usually ultrasound) from a ship down towards the seabed.

The sound wave travels through the water, hits the ocean floor, and bounces back to the ship's receiver. This phenomenon where a wave hits a boundary and returns to the source is known as reflection. By measuring the time it takes for the pulse to return and knowing the speed of sound in water, the depth can be calculated using the formula:

(We divide by 2 because the sound travels to the bottom and back up).

Step-by-Step Solution

1. Diffraction (A): This is the bending of waves around obstacles or through openings. It is not used for depth measurement.
2. Interference (B): This occurs when two waves overlap to form a resultant wave of greater, lower, or the same amplitude. It is not the primary principle for depth measurement.
3. Refraction (C): This is the change in direction of a wave passing from one medium to another due to a change in its speed. While sound waves do refract in water due to temperature changes, it is not the method used to measure depth.
4. Reflection (D): As explained above, the "echo" produced when a sound wave hits the seabed and returns to the surface is a direct result of reflection. This is the fundamental principle of sonar.

Conclusion

Exam Tip

Whenever you see questions about "Echoes," "Sonar," "RADAR," or "Stethoscopes," always associate them with Reflection. These are classic JAMB topics that test your understanding of how waves behave when they hit a hard surface!