Question

Which of the following electromagnetic waves is used in telecommunication? (A) radiowaves (B) visible radiations (C) ultraviolet rays (D) microwaves

Short answer

The correct answer is (A) radio waves, as they have the longest wavelength among the given options and are widely used in communication systems such as radio and television broadcasting, and wireless communication devices like cellphones and Wi-Fi.

Step-by-step solution

1. Understand the different types of electromagnetic waves

electromagnetic waves can be classified into several types, such as radio waves, visible light, ultraviolet radiation, and microwaves. Each type of wave has different properties and uses.

2. Analyze the application of radio waves

Radio waves have the longest wavelength among the given options and have frequencies ranging from 3 kHz to 300 GHz. They are widely used in communication systems such as radio and television broadcasting, and wireless communication devices like cellphones and Wi-Fi.

3. Analyze the application of visible radiations

Visible radiations consist of light that can be seen by the human eye, having wavelengths in the range of 400-700 nm. While they play a crucial role in everyday life, they are not primarily used for telecommunication purposes.

4. Analyze the application of ultraviolet rays

Ultraviolet rays have shorter wavelengths than visible light, ranging from about 100 to 400 nm. They are mainly responsible for the production of vitamin D in our skin and are also used in sterilization processes. However, they are not used in telecommunication.

5. Analyze the application of microwaves

Microwaves have wavelengths ranging from 1 millimeter to 100 centimeters, and are mainly used for cooking in microwave ovens. In addition, they are used in radar systems and satellite communication, making them relevant to the field of telecommunication.

6. Choose the correct answer

Based on the analysis of the applications of the electromagnetic waves provided, it is clear that both radio waves (A) and microwaves (D) are used in telecommunication. However, since radio waves are more commonly used in a wider range of communication systems, including broadcast media and wireless communication devices, the correct answer is (A) radio waves.

Key concepts

Radio Waves

Radio waves are a type of electromagnetic wave with long wavelengths and low frequencies. These waves have wavelengths ranging from about 1 millimeter to over 100 kilometers. Their frequency spectrum spans from roughly 3 kHz up to 300 GHz.

Radio waves are essential in modern telecommunication. They are the backbone of radio and television broadcasts worldwide. This is because of their ability to travel long distances through the air. They are also used in mobile phones, Wi-Fi, and even remote controls.

One of the advantages of radio waves is their ability to pass through obstacles such as buildings or trees, making them ideal for urban environments. However, they can be affected by interference and weather conditions.

• Used in radio and TV broadcasting.
• Essential for Wi-Fi and mobile communications.
• Able to penetrate buildings and obstacles.

Radio waves are divided into several bands, each suited for different applications. For example, the AM (Amplitude Modulation) and FM (Frequency Modulation) bands are used in radio broadcasting, while VHF (Very High Frequency) and UHF (Ultra High Frequency) bands are used in television broadcasting.

Microwaves

Microwaves occupy a middle ground in the electromagnetic spectrum, with wavelengths ranging from 1 millimeter to 1 meter, and frequencies that span from 300 MHz to 300 GHz. These waves are mostly known for their application in microwave ovens, where they are used to heat food.

However, microwaves also play a crucial role in telecommunication. They are utilized for satellite communications, radar systems, and even in some wireless communication technologies.

• Used in microwave ovens for heating food.
• Crucial for satellite and radar communications.
• Less affected by weather conditions than radio waves.

Due to their shorter wavelength compared to radio waves, microwaves can transmit data at higher speeds and with more bandwidth. This makes them suitable for satellite TV and internet services, where large amounts of data need to be sent over long distances.

A distinct advantage of microwaves is their ability to focus into narrow beams. This focused transmission makes them ideal for television signal transmission and point-to-point communication links.

Telecommunication

Telecommunication refers to the transmission of information over distances, often in the form of voice, data, video, and other forms of communication. Central to telecommunication are electromagnetic waves like radio waves and microwaves.

Radio waves are widely used due to their ability to offer coverage over wide areas, making them suitable for broadcast media and mobile networks.

Microwaves, on the other hand, provide higher data transmission capabilities, suitable for satellite communications and long-distance data links.

• Enables exchange of information over large distances.
• Uses electromagnetic waves, especially radio and microwaves.
• Supports both voice and data communications.

Telecommunication systems are critical for the modern world, supporting everything from simple phone calls to complex data exchange over the internet. With ongoing advancements in technology, these systems are constantly improving, offering faster and more reliable communication services.

In summary, while both radio waves and microwaves are used in telecommunication, each serves specific roles leveraged by their unique characteristics, such as wavelength and frequency.