Question 1: Define the electromagnetic spectrum and explain why different regions are used for different communication purposes.

Answer: The electromagnetic spectrum includes all electromagnetic waves arranged by wavelength and frequency. Different regions are used for communication because of their unique properties such as wavelength, frequency, and ability to penetrate various materials.

Question 2: List three types of electromagnetic radiation used specifically in wireless communication.

Answer: Radio waves, microwaves, and infrared radiation.

Question 3: Explain how the wavelength of a wave affects its use in communication.

Answer: Waves with longer wavelengths can travel longer distances and penetrate obstacles, making them suitable for radio and television signals. Shorter wavelengths, like microwaves, are used for satellite and mobile phone communications.

Question 4: A mobile phone operates using microwaves with a frequency of about 2.5 GHz. Calculate the wavelength of this radiation. (Speed of light, c = 3.0 x 10^8 m/s).

Answer: Wavelength = c / frequency = (3.0 x 10^8 m/s) / (2.5 x 10^9 Hz) = 0.12 meters.

Question 5: Identify which part of the EM spectrum is most suitable for satellite communication and explain why.

Answer: Microwaves are most suitable because they can penetrate the Earth's atmosphere and travel long distances with minimal loss.

Question 6: Describe one practical consideration when using high-frequency electromagnetic waves for communication.

Answer: High-frequency waves can be absorbed or scattered by atmospheric conditions like rain, which can disrupt signal transmission.

Question 7: Which safety precautions should be considered when working with high-frequency electromagnetic radiation in communication equipment?

Answer: Avoid prolonged exposure to high-frequency waves, use shielding and safety barriers, and follow manufacturer guidelines.

Question 8: Explain why infrared radiation is used in remote controls for televisions.

Answer: Infrared radiation is used because it is non-ionising, safe for humans, and can be easily modulated to send signals wirelessly.

Question 9: What is the main difference between radio waves and microwaves in their application in communication?

Answer: Radio waves have longer wavelengths and are mainly used for broadcasting and long-distance communication, while microwaves have shorter wavelengths and are used for satellite and mobile phone communication.

Question 10: Why is the use of the electromagnetic spectrum important in modern communication technology?

Answer: It allows for the transmission of data over long distances, supports multiple technologies, and enables wireless communication, making modern life more efficient and connected.

Question 1: Calculate the wavelength of the microwave signals transmitted by the satellite. (Speed of light, c = 3.0 x 10^8 m/s).

Answer: Wavelength = c / frequency = (3.0 x 10^8 m/s) / (12 x 10^9 Hz) = 0.025 meters.

Question 2: If the satellite's antenna has a diameter of 2 metres, what is the approximate wavelength range that the antenna can effectively transmit or receive?

Answer: The antenna is most effective for wavelengths comparable to its size, approximately 1 to 3 metres, but can operate effectively for the calculated wavelength of 0.025 metres with suitable technology.

Question 3: Explain how increasing the frequency of the transmitted wave affects the wavelength and the resolution of the communication signal.

Answer: Increasing the frequency decreases the wavelength, which allows for higher resolution and more precise targeting in communication signals. Shorter wavelengths enable higher data transfer rates but may require more precise equipment and can be more susceptible to atmospheric interference.

Question 4: Discuss one advantage and one disadvantage of using microwaves for satellite communication.

Answer: Advantage: Microwaves can penetrate the Earth's atmosphere and travel long distances with minimal loss, enabling reliable satellite communication. Disadvantage: They are susceptible to atmospheric conditions like rain and fog, which can disrupt signal quality.