Q11. What do you mean by modulation?
Ans. Mixing of low frequency signal with high frequency carrier signal is called modulation. Two signals are involved in modulation process. Messaging signals also known as baseband signals with low frequency and carrier signals with high frequency. The amplitude of baseband signals(low frequency ) is transferred to the high frequency carrier signals which can travel much farther than the baseband signals.
Q12. Explain collision in network?
Ans. A network collision occurs when two or more devices attempt to transmit data over a network at the same time. For example, if two computers on an Ethernet network send data at the same moment, the data will “collide” and not finish transmitting.
Q13. Give one advantage and one disadvantage of Optical Fibre Cable.
Ans. Advantages: Not affected by any kind of noise., High transmission capacity, Speed of Light, Suitable for broadband communication
Disadvantages: Installation requires care., Connecting two Optical fibers is difficult., Optical fibers are more difficult to solder
Q14. What is NIC?
Ans. A network card, network adapter or NIC (network interface card) is a piece of computer hardware designed to allow computers to communicate over a computer network. NIC or LAN Card or Network Interface Unit(NIU) enables a computer to connect with a network using a port. It allows users to connect to each other either by using cables or wirelessly. WLANS Cards are also used for connecting PCs with wireless network.
Q15. What are protocols? give some examples of protocols.
Ans. A protocol is a system of rules that allows two or more entities of a communication system to transmit informaton via any kind of variation of a physical quantity.
Q16. Differentiate between apmlitude and frequency modulation.
Ans. Amplitude modulation:- A type of modulation where the amplitude of the carrier signal is modulated (changed) in proportion to the message signal while the frequency and phase are kept constant.
Frequency modulation:- A type of modulation where the frequency of the carrier signal is modulated (changed) in proportion to the message signal while the amplitude and phase are kept constant.
Q17. What do you understand by error checking and error detection codes?
Ans. In networking, error detection refers to the techniques used to detect noise or other impairments introduced into data while it is transmitted from source to destination. Error detecting codes are used which are additional data added to a given digital message to help us detect if an error occurred during transmission of the message. Along with this some data is passed to figure out the original message from the corrupt message.
Q18. What is routing table? what type of informaton is stored in routing table.
Ans. Routers use Routing Tables to determine out which interface the packet will be sent. A routing table lists all networks for which routes are known. Each router’s routing table is unique and stored in the RAM of the device. A routing table is a set of rules, often viewed in table format, that is used to determine where data packets traveling over an Internet Protocol (IP) network will be directed.
Q19. Write a shortnote on MAC.
Ans. MAC Addresses are unique 48-bits hardware number of a computer, which is embedded into network card (known as Network Interface Card) during the time of manufacturing. MAC Address is also known as Physical Address of a network device. A MAC address is a hardware identification number that uniquely identifies each device on a network. MAC addresses are made up of six two-digit hexadecimal numbers, separated by colons. For example, an Ethernet card may have a MAC address of 00:0d:83:b1:c0:8e. every hexadecimal characters represents 4 bits, so the first six hexadecimal characters represent the manufacturer’s or vendor’s number.
Q20. Write a shortnote on IPv4 addressing.
Ans. An IP address is a unique address of each device(computer or any other network device) connected to a network. It is a series of four numbers each ranging from 0 to 255 separated by dots or periods. (e.g 192.168.1.1).
An IPv4 address is a 32 bit addressing scheme and has following format : x.x.x.x, where x is called an octet and must be a decimal value between 0 to 255. Octets are separated by periods. An IPv4 address must contain three periods and four octets.