Question

Which of the following principles is being used in sonar technology?
A. Newton’s law of motion
B. Reflection of electromagnetic waves
C. Law of thermodynamics
D. Reflection of ultrasonic waves

Answer 1

Hint: First let us see what sonar technology is-
Sonar is a method that uses sound propagation (usually underwater, as in submarine navigation) to track, interact with or locate objects, such as other vessels on or under the surface of the sea.
The sonar instrument tests how long it takes to move down the sound wave, strike an item, and then bounce back up.

Complete step by step answer:
Newton’s law of motion- There are three laws of motion which are known as the Newton’s laws of motion. The first law states that a physical quantity called force is required to push and pull an object from its state of rest. An object will not change its position unless compelled to do so. Newton’s second law states that force is directly proportional to mass and acceleration. So force is equal to mass times acceleration. Newton’s third law states that every action has an equal and opposite reaction.
Reflection of electromagnetic waves- The reflection of electromagnetic waves includes the return or throwing back of the waves by the wave incident surface. The boundary between two materials with different electromagnetic properties is generally a reflecting surface.
Law of thermodynamics- There are three laws of thermodynamics:
The first law of thermodynamics, also known as the law of conservation of energy, states that it is not possible to create or destroy energy; it is only possible to transfer or change energy from one form to another. The second law of thermodynamics says that any isolated system’s entropy always increases. Spontaneously, isolated systems evolve towards thermal equilibrium, the state of maximum system entropy. The third law of thermodynamics states that, as the temperature approaches absolute zero, the entropy of a system approaches a constant value. Typically the entropy of a system at absolute zero is zero, and in all cases, it is only determined by the number of different soil states it has.
Reflection of ultrasonic waves- An ultrasonic wave reflection occurs when the wave passes between two tissues of distinct acoustic velocities and a fraction of the wave bounces back. This forms one of the main principles of ultrasound imaging as these reflected waves are detected by the ultrasound probe to form the desired image. This very principle is used in sonar technology.

So, the correct answer is “Option D”.

Note:
Pulses of sound waves are sent down through the water by a sonar device. They are reflected back to the surface when these pulses hit objects such as fish, vegetation or the bottom. The sonar instrument measures how long it takes to travel down, hit an object and then reflect back.