Cellular phones use:
1) radar waves
2)very high-frequency waves
3)very low-frequency waves
4)microwaves****
UHF or microwaves is a good answer.
Why did you post this twice?
To verify the correct answer, we can explain each option and determine which one matches the technology used in cellular phones.
1) Radar Waves: Radar waves are typically used for detecting the presence, distance, and speed of objects. They are commonly used in applications such as air traffic control or meteorology. While radar waves share some similarities with the technology used in mobile phones, they are not the primary type of waves used.
2) Very High-Frequency Waves: Very high-frequency waves, often referred to as VHF waves, have frequencies ranging from 30 MHz to 300 MHz. While these waves are used for various applications, including broadcasting radio and television signals, they are not the primary type of waves used in cellular phones.
3) Very Low-Frequency Waves: Very low-frequency waves, often referred to as VLF waves, have frequencies ranging from 3 kHz to 30 kHz. These waves are commonly used for long-distance communications, such as submarine communication or broadcasting radio signals over a large area. However, VLF waves are not the primary type of waves used in cellular phones.
4) Microwaves: Microwaves, with frequencies typically ranging from 1 GHz to 300 GHz, are the correct answer. They fall within the range of radio waves and are used extensively for wireless communication. Cellular phones use microwaves to transmit and receive signals for voice calls, text messages, and data transfer.
Therefore, the correct answer is 4) microwaves.