Long Answer Type Questions: Computer Networking | Computer Science for Grade 9 PDF Download

Q.1. State two advantages and disadvantages of Bluetooth.

Advantages

• Connection establishment is very quick and easy, you just need to pair the Bluetooth PAN connection between two devices.
• It has low power consumption.
• It can pass through walls unlike Infrared.

Disadvantages

• Bluetooth communication is insecure.
• It is used only for short range communication.
• Power consumption is very high compared to a condition when Bluetooth is powered off.

Q.2. Why are satellite links used even though it is expensive?

Even though these systems are expensive, the area it covers compensate for the expenses. The communication satellites are generally owned by governments or by government approved organizations of various countries.

Q.3. What is an optical fibre? What are its different components?

Optical Fibers consist of thin strands of long glass whose thickness of that of a human hair. These wires are arranged in bundles which are technically called optical fiber cables and used to transmit data through light signals over long distances using the principle of Total Internal Reflection. It transmits an optical fiber has following parts:

• Core - It is the thin glass rod at the center through which the light travels
• Cladding - It is the outer optical material surrounding the core that reflects the light back into the core
• Buffer coating - It is the plastic coating that protects the cable from damage and moisture

Q.4. Write a short note on Radio Waves.

Radio waves have a frequency ranging from 3 KHz to 3GHz. It is used for communication over short distances like from a few meters (as in walkie-talkies) upto covering an entire city. It is easier to generate these waves and can travel long distances and is able to penetrate buildings easily. This makes it widely used in both indoor and outdoor communication.

Q.5. What is WiMAX?

WiMAX (Worldwide Interoperability for Microwave Access) is a wireless communications standard designed to provide 30 to 40 megabits-per-second data rates. WiMax requires a tower called WiMax Base Station, similar to a cell phone tower, which is connected to the Internet using a standard wired high-speed connection. But as opposed to a traditional Internet Service Provider (ISP), which divides that bandwidth among customers via wire, it uses a microwave link to establish a connection. In other words, WiMax does not depend on cables to connect each endpoint, the Internet connectivity to an end-user is provided through microwave link between the tower and the user-endpoint, known as Wi-Max subscriber unit.