Computer Networks

This is the correct option and DSL modems are used to connect computers having ethernet cables.

This was the first wireless Local Area Network.

This supplementary service in GSM network refers to a service enabled by a subscriber by barring either incoming or outgoing call.

This network refers to the international telephone system based on copper wires carrying analog voice data.

Network is the interconnection of two or more computers. 

Yes it's correct choice. An extranet actually combines both the Internet and an intranet. It extends an intranet, or internal network to other users over the Internet.

It is the hardware, which helps to connect to the internet.

LAN covers a small distance, typically within a single building or a college campus. It's connectivity range is actual 2 kms. LAN can share resources and other devices and also communicate with in 2 kms.

The computer networks make resources available to any one on the network regardless of the physical location of the resource or the user. The files can be shared in a computer network in two ways. The one way is to transmit the file or data form your computer to the other computer directly. The other way is to send data to an intermediate place, from where the other person can pick it up later.

Bandwidth is the number of bits processed in a single instruction. It is the total maximum capacity of a network connection. Wide Area Network processed 10 kbps-600 mbps in a single instruction.

It is designed with each node which is connected directly to central network hub or concentrator. Usually the central node has the peripherals that are to be shared across the network attached to it and often it acts as a file and printer server to the rest of the stations on the network. The hub or concentrator manages and controls all functions of the network. Concentrator is also called hub.

It is a device that connects two or more networks. It receives data from one side and determine, is destination on the other side of router. If yes, than packet is forwarded; If no, it will forwarded the packets to next router. So it controls the data transmission traffic.

 Modem is a device that translates the digital signals of computer into analog signals which can travel across conventional phone lines. It is the combination of modulation and demodulation. Modulation means converting signals digital to analog and Demodulation mean converting signals analog to digital. 

 This is correct. NIC stands for Network Interface Card.

Ring topology are wired in circle. Each node (computer) is connected to its neighbors on either side. The last node gets connected to first node and data passes around the ring in one direction only. It is easy to install. In this addition and removal of computers in already existing network is difficult. If any one node goes down or damage than whole network goes down.