Introduction to Wireless Communication

Who invented the wireless telegraph in 1896?

• Nikola Tesla

• Thomas Edison

• Alexander Graham Bell

• Guglielmo Marconi

Answer explanation

Guglielmo Marconi invented the wireless telegraph in 1896, making him the correct choice for this question.

What is the frequency range of microwave signals?

• 1 GHz to 40 GHz

• 1 Hz to 1 kHz

• 50 GHz to 100 GHz

• 200 MHz to 1 GHz

Answer explanation

Microwave signals have a frequency range of 1 GHz to 40 GHz, making the correct answer choice 1 GHz to 40 GHz.

Which type of media guides electromagnetic signals along a solid path?

• Optical fiber

• Unguided media

• Wireless transmission

• Atmosphere

Answer explanation

Optical fiber is the type of media that guides electromagnetic signals along a solid path, making it the correct choice among the options provided.

What is the main application of terrestrial microwave antennas?

• Long haul telecommunications

• Infrared transmission

• Broadcast radio

• Satellite communication

Answer explanation

The main application of terrestrial microwave antennas is for long haul telecommunications, enabling the transmission of data over long distances efficiently.

What is the frequency range of infrared signals?

• 1 Hz to 1 kHz

• 10¹² Hz to 10¹⁴ Hz

• 200 MHz to 1 GHz

• 50 GHz to 100 GHz

Answer explanation

The correct frequency range of infrared signals is 10^12 Hz to 10^14 Hz.

Which type of transmission media does not guide electromagnetic signals?

• Copper twisted pair

• Copper coaxial cable

• Unguided media

• Optical fiber

Answer explanation

Unguided media does not guide electromagnetic signals, unlike copper twisted pair, copper coaxial cable, and optical fiber.

What is the purpose of a parabolic 'dish' antenna in microwave transmission?

• Broadcast radio

• Infrared transmission

• Line-of-sight transmission

• Omnidirectional transmission

Answer explanation

A parabolic 'dish' antenna is used for line-of-sight transmission in microwave communication, focusing the signal in a specific direction for better range and signal strength.

Which frequency range is suitable for omnidirectional applications?

• 1 GHz to 40 GHz

• 30 MHz to 1 GHz

• 10^12 Hz to 10^14 Hz

• 1 Hz to 1 kHz

Answer explanation

The suitable frequency range for omnidirectional applications is 30 MHz to 1 GHz, as it provides a good balance between coverage and efficiency.

What is the main application of broadcast radio antennas?

• Private business networks

• Short point-to-point links

• Television distribution

• Long haul telecommunications

Answer explanation

The main application of broadcast radio antennas is television distribution, as they are used to transmit TV signals over long distances to reach a wide audience.

What is the characteristic of infrared signals regarding walls?

• Penetrates walls easily

• Requires line of sight

• Reflects off walls

• Absorbed by walls

Answer explanation

Infrared signals are absorbed by walls, making it difficult for them to penetrate through walls.