Human ears are capable of hearing from 20 Hz to 20000 Hz. If the frequency is higher or lower than this, the human ear will not be able to perceive it.

A lion's roar is very loud and its frequency is low, which results in a low pitch.

Ultra High Frequency (UHF) are radio waves with a frequency ranging from 300 MHz to 3000 MHz. These waves are transmitted through space waves.

The maximum disturbance on either side of the original position in a medium is called the amplitude of the wave. The loudness or softness of a sound is basically determined by its amplitude.

MRI means Magnetic Resonance Imaging. In this medical method, the patient is admitted inside the MRI machine and tested using magnetic rays.

Sound propagation occurs in all media in the form of longitudinal waves. These waves travel in the form of compressions and rarefactions.

Before transmission, television picture signals are Amplitude Modulated, while sound signals are Frequency Modulated.

According to the World Health Organization and other standards, noise greater than 75-80 decibels is considered painful and harmful for the human body.

According to international standards to control noise pollution in hospitals, libraries, and quiet zones, up to 65 dB of sound is considered the limit of tolerance.

The level of a normal whisper is 30 decibels. When two people talk normally to each other, the sound level is generally between 30 and 60 decibels, where 30 decibels is an accepted value.

Radio waves are examples of wireless communication.

Sound waves are mechanical waves that require a medium to propagate. They can travel through solids, liquids, and gases. They cannot travel in a vacuum.

Sonar (Sound Navigation and Ranging) instrument detects objects submerged in the sea through sound transmission. In this method, ultrasonic waves are used.

The pitch of sound depends on frequency; as the frequency of sound increases, the pitch also increases.

The speed of sound is highest in solid media, followed by liquid, and then gas. Steel (metal) is a solid medium, so the speed of sound is highest in it. Sound cannot propagate in a vacuum.

When moisture is removed from the air, its density increases. The speed of sound in a medium is inversely proportional to the square root of its density. The lower the density, the faster the sound travels. Therefore, the speed of sound in moist air is greater than in dry air.

Optical fiber is a device based on the principle of total internal reflection, through which light waves can be transferred from one place to another without any decay in their frequency. It is a fiber made of glass or plastic, through which light can propagate in the direction of its length. The optical fiber transmits and receives by converting electrical signals into light signals.

Infrared Rays - Infrared rays are a type of electromagnetic radiation that is emitted when objects are hot, hence they are used in TV remotes.

In frequency modulation (Frequency Modulation/FM), the frequency band for FM transmission is between 88 and 108 MHz.

Fundamental frequency of pipe A (open pipe): $V_A = \frac{V}{2L}$. Fundamental frequency of pipe B (closed at one end): $V_B = \frac{V}{4L}$. Ratio: $\frac{V_A}{V_B} = \frac{V/2L}{V/4L} = 2:1$.