Question

The ultra-high frequency band of radio waves in electromagnetic wave is used as in:
A. Television waves
B. Cellular phone communication
C. Commercial FM radio
D. Both A and C

Answer 1

Hint:Ultra-high frequency (UHF) is defined as the portion of electromagnetic spectrum surrounding radiations having radio frequency between 300 megahertz and 3 gigahertz.

Complete step-by-step solution:
The Ultra-high frequency (UHF) is the International Telecommunication Union agency given name for radio frequencies who lie between 300 MHz and 3 GHz.
The Ultra-high frequency band is used for satellite communication as well as cellular phone communications because the frequency in the range is high and the band is wide with a span of 2.7 GHz from the low end to high end which makes the wideband modulation and spread spectrum modes practical. It is of the order ${10^9}$ Hz. They are blocked by large objects like mountains or large buildings but can penetrate buildings for indoor reception. These radio waves propagate by a line of sight propagation and ground reflection. Also, their transmitting antennas are small to install in portable devices which is another reason why they are used in cellular phone communication.
Hence, option (B) Cellular phone communication is correct.

Note:- Ultra high frequency has a wavelength range of 1 m to 3 dm. They are sometimes referred to as 800 MHz systems and also as decimeter bands. Other applications of UHF are two-way radios for voice communication in commercial, industry, public safety and military purposes.