McqMate
| 1. |
When collection of various computers seems a single coherent system to its client, then it is called |
| A. | computer network |
| B. | distributed system |
| C. | networking system |
| D. | mail system |
| Answer» B. distributed system | |
| Explanation: a computer network is defined as a collection of interconnected computers which uses a single technology for connection. | |
| 2. |
Two devices are in network if |
| A. | a process in one device is able to exchange information with a process in another device |
| B. | a process is running on both devices |
| C. | pids of the processes running of different devices are same |
| D. | a process is active and another is inactive |
| Answer» A. a process in one device is able to exchange information with a process in another device | |
| Explanation: a computer network, or data network, is a digital telecommunications network which allows nodes to share resources. in computer networks, computing devices exchange data with each other using connections between nodes. the nodes have certain processes which enable them to share a specific type of data using a distinct protocol. | |
| 3. |
Which of the following computer networks is built on the top of another network? |
| A. | prior network |
| B. | chief network |
| C. | prime network |
| D. | overlay network |
| Answer» D. overlay network | |
| Explanation: an overlay network is a computer network that is built on top of another network. some examples of an overlay network are virtual private networks (vpn) and peer-to-peer networks (p2p). | |
| 4. |
In computer network nodes are |
| A. | the computer that originates the data |
| B. | the computer that routes the data |
| C. | the computer that terminates the data |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: in a computer network, a node can be anything that is capable of sending data or receiving data or even routing the data to its destination. routers, computers and smartphones are some examples of network nodes. | |
| 5. |
Communication channel is shared by all the machines on the network in |
| A. | broadcast network |
| B. | unicast network |
| C. | multicast network |
| D. | anycast network |
| Answer» A. broadcast network | |
| Explanation: in a broadcast network, information is sent to all stations in a network whereas in a multicast network the data or information is sent to a group of stations in the network. in unicast network, information is sent to only one specific station. the broadcast address of the network is the last assigned address of the network. | |
| 6. |
Bluetooth is an example of |
| A. | personal area network |
| B. | local area network |
| C. | virtual private network |
| D. | wide area network |
| Answer» A. personal area network | |
| Explanation: bluetooth is a wireless technology used to create a wireless personal area network for data transfer up to a distance of 10 meters. it operates on 2.45 ghz frequency band for transmission. | |
| 7. |
A is a device that forwards packets between networks by processing the routing information included in the packet. |
| A. | bridge |
| B. | firewall |
| C. | router |
| D. | hub |
| Answer» C. router | |
| Explanation: a router is a networking device that forwards data packets between computer networks. routers perform the traffic directing functions on the internet. they make use of routing protocols like rip to find the cheapest path to the destination. | |
| 8. |
A list of protocols used by a system, one protocol per layer, is called |
| A. | protocol architecture |
| B. | protocol stack |
| C. | protocol suite |
| D. | protocol system |
| Answer» B. protocol stack | |
| Explanation: a protocol stack refers to a group of protocols that are running concurrently that are employed for the implementation of network protocol suite. each layer in the network model has to use one specific protocol from the protocol stack. | |
| 9. |
Network congestion occurs |
| A. | in case of traffic overloading |
| B. | when a system terminates |
| C. | when connection between two nodes terminates |
| D. | in case of transfer failure |
| Answer» A. in case of traffic overloading | |
| Explanation: network congestion occurs when traffic in the network is more than the network could handle. to avoid network congestion, the network management uses various open-loop and closed-loop congestion control techniques. | |
| 10. |
Which of the following networks extends a private network across public networks? |
| A. | local area network |
| B. | virtual private network |
| C. | enterprise private network |
| D. | storage area network |
| Answer» B. virtual private network | |
| Explanation: a virtual private network extends a private network across a public network, and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network.vpn provides enhanced security and online anonymity to users on the internet. it is also used to unblock websites which are unavailable in certain regions. | |
| 11. |
Physical or logical arrangement of network is |
| A. | topology |
| B. | routing |
| C. | networking |
| D. | control |
| Answer» A. topology | |
| Explanation: topology in networks is the structure or pattern in which each and every node in the network is connected. there are many topologies in networking like bus, tree, ring, star, mesh, and hybrid topology. there is no particular best topology and a suitable topology can be chosen based on the kind of application of the network . | |
| 12. |
Which network topology requires a central controller or hub? |
| A. | star |
| B. | mesh |
| C. | ring |
| D. | bus |
| Answer» A. star | |
| Explanation: in star topology, no computer is connected to another computer directly but all the computers are connected to a central hub. every message sent from a source computer goes through the hub and the hub then forwards the message only to the intended destination computer. | |
| 13. |
topology requires a multipoint connection. |
| A. | star |
| B. | mesh |
| C. | ring |
| D. | bus |
| Answer» D. bus | |
| Explanation: in bus topology, there is a single cable to which all the network nodes are connected. so whenever a node tries to | |
| 14. |
Data communication system spanning states, countries, or the whole world is |
| A. | lan |
| B. | wan |
| C. | man |
| D. | pan |
| Answer» B. wan | |
| Explanation: wan is the abbreviation for wide area network. this network extends over a large geographical area. wans are used to connect cities, states or even countries. a wireless connection is required to build a wan. the best example of wan is the internet. | |
| 15. |
Data communication system within a building or campus is |
| A. | lan |
| B. | wan |
| C. | man |
| D. | pan |
| Answer» A. lan | |
| Explanation: lan is an abbreviation for local area network. this network interconnects computers in a small area such as schools, offices, residence etc. it is the most versatile kind of data communication system where most of the computer network concepts can be visibly used. | |
| 16. |
WAN stands for |
| A. | world area network |
| B. | wide area network |
| C. | web area network |
| D. | web access network |
| Answer» B. wide area network | |
| Explanation: wan is the abbreviation for wide area network. this network extends | |
| 17. |
In TDM, slots are further divided into |
| A. | seconds |
| B. | frames |
| C. | packets |
| D. | bits |
| Answer» B. frames | |
| Explanation: tdm is the abbreviation for time division multiplexing. it is technique for combining several low rate channels to a single high rate channel. for a certain time slot, the several channels could use the maximum bandwidth. each channel is inactive for a period of time too. some other multiplexing techniques are frequency division multiplexing and phase division multiplexing. | |
| 18. |
is the multiplexing technique that shifts each signal to a different carrier frequency. |
| A. | fdm |
| B. | tdm |
| C. | both fdm & tdm |
| D. | pdm |
| Answer» A. fdm | |
| Explanation: fdm is an abbreviation for frequency division multiplexing. this technique is used when the bandwidth of the channel is greater than the combined bandwidth of all the signals which are to be transmitted. the channel is active at all times unless a collision occurs with another channel trying to use the same frequency. some other multiplexing techniques are time division multiplexing and phase division multiplexing. | |
| 19. |
What is internet? |
| A. | a single network |
| B. | a vast collection of different networks |
| C. | interconnection of local area networks |
| D. | interconnection of wide area networks |
| Answer» B. a vast collection of different networks | |
| Explanation: internet is nothing but an interconnected computer network providing a variety of communication facilities, consisting of a huge amount of small networks using standardized communication protocols. | |
| 20. |
To join the internet, the computer has to be connected to a |
| A. | internet architecture board |
| B. | internet society |
| C. | internet service provider |
| D. | different computer |
| Answer» C. internet service provider | |
| Explanation: the isps (internet service providers) are the main agents through which every computer is connected to the internet. they are licensed to allot public ip addresses to its customers in order to connect them to the internet. | |
| 21. |
Internet access by transmitting digital data over the wires of a local telephone network is provided by |
| A. | leased line |
| B. | digital subscriber line |
| C. | digital signal line |
| D. | digital leased line |
| Answer» B. digital subscriber line | |
| Explanation: dsl (digital subscriber line) is the technology designed to use the existing telephone lines to transport high-bandwidth data to service subscribers. dsl was used to allow the early users access to the internet and it provides dedicated, point-to-point, public network access. | |
| 22. |
3 OVERVIEW OF INTERNET |
| A. | internet exchange point |
| B. | subscriber end point |
| C. | isp end point |
| D. | internet end point |
| Answer» A. internet exchange point | |
| Explanation: isps exchange internet traffic between their networks by using internet exchange points. isps and cdns are connected to each other at these physical locations are they help them provide better service to their customers. | |
| 23. |
Which of the following protocols is used in the internet? |
| A. | http |
| B. | dhcp |
| C. | dns |
| D. | dns, http and dns |
| Answer» D. dns, http and dns | |
| Explanation: http is used to browse all the websites on the world wide web, dhcp is used to allot ips automatically to the users on the internet, and dns is used to connect the users to the host servers on the internet based on the domain name. | |
| 24. |
Internet works on |
| A. | packet switching |
| B. | circuit switching |
| C. | both packet switching and circuit switching |
| D. | data switching |
| Answer» A. packet switching | |
| Explanation: packet switching is the method based on which the internet works. packet switching features delivery of packets of data between devices over a shared network. | |
| 25. |
Which one of the following is not an application layer protocol used in internet? |
| A. | remote procedure call |
| B. | internet relay chat |
| C. | resource reservation protocol |
| D. | local procedure call |
| Answer» C. resource reservation protocol | |
| Explanation: resource reservation protocol is a transport layer protocol used on the internet. it operates over ipv4 and ipv6 and is designed to reserve resources required by the network layer protocols. | |
| 26. |
Which protocol assigns IP address to the client connected in the internet? |
| A. | dhcp |
| B. | ip |
| C. | rpc |
| D. | rsvp |
| Answer» A. dhcp | |
| Explanation: dhcp stands for domain host control protocol. it is responsible to remotely assign ip address to the clients connected to the internet. the server that performs this fuction is called the dhcp server. | |
| 27. |
Which one of the following is not used in media access control? |
| A. | ethernet |
| B. | digital subscriber line |
| C. | fiber distributed data interface |
| D. | packet switching |
| Answer» D. packet switching | |
| Explanation: packet switching is not really related to media access control as it just features delivery of packets of data between devices over a shared network. internet is actually based on packet switching. | |
| 28. |
Which level is the network layer in the OSI model? |
| A. | third level |
| B. | fourth level |
| C. | second level |
| D. | fifth layer |
| Answer» A. third level | |
| Explanation: the network layer is the third level of the open system interconnection model and the layer that provides data routing paths for network communication. | |
| 29. |
Data in network layer is transferred in the form of |
| A. | layers |
| B. | packets |
| C. | bytes |
| D. | bits |
| Answer» B. packets | |
| Explanation: data is transferred in the form of packets via logical network paths in an ordered format controlled by the network layer. | |
| 30. |
The network layer contains which hardware device? |
| A. | routers, bridges |
| B. | bridges only |
| C. | bridges and switches |
| D. | routers, bridges and switches |
| Answer» D. routers, bridges and switches | |
| Explanation: this layer contains hardware devices such as routers, bridges, firewalls, and switches, but it actually creates a logical image of the most efficient communication rout and implements it with a physical medium. | |
| 31. |
Network layer protocol exits in |
| A. | host |
| B. | switches |
| C. | packets |
| D. | bridges |
| Answer» A. host | |
| Explanation: network layer protocols exits in every host or router. the router examines the header fields of all the ip packets that pass through it. | |
| 32. |
What are the common protocols associated with the network layer? |
| A. | address resolution protocol |
| B. | reverse address resolution protocol |
| C. | internet protocol |
| D. | neighbour discovery protocol |
| Answer» C. internet protocol | |
| Explanation: internet protocol and netware ipx/spx are the most common protocols associated with the network layer. | |
| 33. |
The network layer responds to request from which layer? |
| A. | transport layer |
| B. | data layer |
| C. | application layer |
| D. | session layer |
| Answer» A. transport layer | |
| Explanation: in osi model, we are having 7 layers in which the network layer responds to request from the layer above it called transport layer. | |
| 34. |
The network layer issues request to which layer? |
| A. | transport layer |
| B. | data layer |
| C. | application layer |
| D. | session layer |
| Answer» B. data layer | |
| Explanation: in osi model, we are having 7 layers in which the network layer issues request to the layer below it called data link layer. | |
| 35. |
IP is connectionless. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: ip is connectionless, is that a data packet can travel from a sender to a receiver without the recipient having to send an acknowledgment connection-oriented protocols exits at other, higher layers of the osi model. | |
| 36. |
Does network layer in TCP/IP and OSI Model are same. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: the tcp/ip internet layer is in fact only a subset of functionality of the network layer. it describes only one type of network architecture, the internet. | |
| 37. |
What are called routers? |
| A. | the devices that operates at session layer |
| B. | the devices that operates at data layer |
| C. | the devices that operates at application layer |
| D. | the devices that operates at network |
| Answer» D. the devices that operates at network | |
| Explanation: the network interconnection devices that operate at the network layer are usually called routes, which at this point should hopefully come as no surprise to you. | |
| 38. |
ICMP stands for |
| A. | internet coordinate message protocol |
| B. | internet control message protocol |
| C. | interconnect control message protocol |
| D. | interconnect coordinate message protocol |
| Answer» B. internet control message protocol | |
| Explanation: the internet protocol is the key network layer protocol that implements the tcp/ip protocol suites. since ip is the protocol that provides the mechanism for delivering datagrams, between devices, it is designed to be relatively basic, and to function with few “bell and whistles”. | |
| 39. |
Packets will be transferred in how many types? |
| A. | 5 types |
| B. | 4 types |
| C. | 2 types |
| D. | 3 types |
| Answer» D. 3 types | |
| Explanation: routing deals with determining how packet will routed (transferred) from source to destination. it can of three types : 1. static | |
| 40. |
DDP stands for |
| A. | datagram delivery protocol |
| B. | device delivery protocol |
| C. | datagram device protocol |
| D. | device datagram protocol |
| Answer» A. datagram delivery protocol | |
| Explanation: datagram delivery protocol is a member of the appletalk networking protocol suite. its main responsibility is for socket to socket delivery of datagram over an appletalk network. | |
| 41. |
RIP stands for |
| A. | reduced information protocol |
| B. | routing internet protocol |
| C. | routing information protocol |
| D. | reduced internet protocol |
| Answer» C. routing information protocol | |
| Explanation: the routing information protocol is one of the oldest distance vector routing protocols which employ the hop count as a routing metric. | |
| 42. |
The model is 7-layer architecture where each layer is having some specific functionality to perform. |
| A. | tcp/ip |
| B. | cloud |
| C. | osi |
| D. | ois |
| Answer» C. osi | |
| Explanation: the osi model is 7-layer architecture where each layer is having some specific functionality to perform. all these layers work in collaboration for transmitting the data from 1 person to another worldwide. | |
| 43. |
The full form of OSI is OSI model is |
| A. | open systems interconnection |
| B. | open software interconnection |
| C. | open systems internet |
| D. | open software internet |
| Answer» A. open systems interconnection | |
| Explanation: the osi model is 7-layer architecture where each layer is having some specific functionality to perform. all these layers work in collaboration for transmitting the data from 1 person to another worldwide. | |
| 44. |
Which of the following is not physical layer vulnerability? |
| A. | physical theft of data & hardware |
| B. | physical damage or destruction of data & hardware |
| C. | unauthorized network access |
| D. | keystroke & other input logging |
| Answer» C. unauthorized network access | |
| Explanation: unauthorized network access is | |
| 45. |
In layer, vulnerabilities are directly associated with physical access to networks and hardware. |
| A. | physical |
| B. | data-link |
| C. | network |
| D. | application |
| Answer» A. physical | |
| Explanation: in the physical layer, vulnerabilities are directly associated with physical access to networks and hardware such as unauthorised network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 46. |
Loss of power and unauthorized change in the functional unit of hardware comes under problems and issues of the physical layer. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: loss of power and unauthorized change in the functional unit of hardware comes under problems and issues of the physical layer. other such issues are unauthorised network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 47. |
Which of the following is not a vulnerability of the data-link layer? |
| A. | mac address spoofing |
| B. | vlan circumvention |
| C. | switches may be forced for flooding traffic to all vlan ports |
| D. | overloading of transport-layer mechanisms |
| Answer» D. overloading of transport-layer mechanisms | |
| Explanation: mac address spoofing, vlan circumvention and switches may be | |
| 48. |
is data-link layer vulnerability where stations are forced to make direct communication with another station by evading logical controls. |
| A. | vlan attack |
| B. | vlan circumvention |
| C. | vlan compromisation method |
| D. | data-link evading |
| Answer» B. vlan circumvention | |
| Explanation: vlan circumvention is data- link layer vulnerability where stations are forced to make direct communication with another station by evading logical controls implemented using subnets and firewalls. | |
| 49. |
may be forced for flooding traffic to all VLAN ports allowing interception of data through any device that is connected to a VLAN. |
| A. | switches |
| B. | routers |
| C. | hubs |
| D. | repeaters |
| Answer» A. switches | |
| Explanation: switches may be forced for flooding traffic to all vlan ports allowing interception of data through any device that are connected to a vlan. it is a vulnerability of data link layer. | |
| 50. |
Which of the following is not a vulnerability of the network layer? |
| A. | route spoofing |
| B. | identity & resource id vulnerability |
| C. | ip address spoofing |
| D. | weak or non-existent authentication |
| Answer» D. weak or non-existent authentication | |
| Explanation: weak or non-existent authentication is a vulnerability of the session layer. route spoofing, identity & resource id vulnerability & ip address spoofing are examples of network layer vulnerability. | |
| 51. |
Which of the following is an example of physical layer vulnerability? |
| A. | mac address spoofing |
| B. | physical theft of data |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» B. physical theft of data | |
| Explanation: physical theft of data is an example of physical layer vulnerability. other such issues are unauthorized network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 52. |
Which of the following is an example of data-link layer vulnerability? |
| A. | mac address spoofing |
| B. | physical theft of data |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» A. mac address spoofing | |
| Explanation: mac address spoofing is an example of data-link layer vulnerability. | |
| 53. |
Which of the following is an example of network layer vulnerability? |
| A. | mac address spoofing |
| B. | physical theft of data |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» C. route spoofing | |
| Explanation: route spoofing is an example of network layer vulnerability. other examples of network layer vulnerabilities are ip address spoofing and identity & resource id vulnerability. | |
| 54. |
Which of the following is an example of physical layer vulnerability? |
| A. | mac address spoofing |
| B. | route spoofing |
| C. | weak or non-existent authentication |
| D. | keystroke & other input logging |
| Answer» D. keystroke & other input logging | |
| Explanation: keystroke & other input logging is an example of physical layer vulnerability. other such physical layer vulnerabilities are unauthorized network access, damage or destruction of data & hardware and keystroke & other input logging. | |
| 55. |
Which of the following is an example of data-link layer vulnerability? |
| A. | physical theft of data |
| B. | vlan circumvention |
| C. | route spoofing |
| D. | weak or non-existent authentication |
| Answer» B. vlan circumvention | |
| Explanation: vlan circumvention is an example of data-link layer vulnerability. mac address spoofing, as well as switches, may be forced for flooding traffic to all vlan ports are some other examples of data-link layer vulnerability. | |
| 56. |
Which transmission media provides the highest transmission speed in a network? |
| A. | coaxial cable |
| B. | twisted pair cable |
| C. | optical fiber |
| D. | electrical cable |
| Answer» C. optical fiber | |
| Explanation: fiber optics is considered to have the highest transmission speed among the all mentioned above. the fiber optics transmission runs at 1000mb/s. it is called as 1000base-lx whereas ieee standard for it is 802.3z. it is popularly used for modern day network connections due to its high transmission rate. | |
| 57. |
Bits can be sent over guided and unguided media as analog signal by |
| A. | digital modulation |
| B. | amplitude modulation |
| C. | frequency modulation |
| D. | phase modulation |
| Answer» A. digital modulation | |
| Explanation: in analog modulation, digital low frequency baseband signal (digital bit stream) is transmitted over a higher frequency. whereas in digital modulation the only difference is that the base band signal is of discrete amplitude level. the bits are represented by only two frequency levels, one for high and one for low. | |
| 58. |
The portion of physical layer that interfaces with the media access control sublayer is called |
| A. | physical signalling sublayer |
| B. | physical data sublayer |
| C. | physical address sublayer |
| D. | physical transport sublayer |
| Answer» A. physical signalling sublayer | |
| Explanation: the portion of physical layer that interfaces with the medium access control sublayer is physical signaling sublayer. the main function of this layer is character encoding, reception, decoding and performs optional isolation functions. it | |
| 59. |
The physical layer provides |
| A. | mechanical specifications of electrical connectors and cables |
| B. | electrical specification of transmission line signal level |
| C. | specification for ir over optical fiber |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: anything dealing with a network cable or the standards in use – including pins, connectors and the electric current used is dealt in the physical layer (layer 1). physical layer deals with bit to bit delivery of the data aided by the various transmission mediums. | |
| 60. |
In asynchronous serial communication the physical layer provides |
| A. | start and stop signalling |
| B. | flow control |
| C. | both start & stop signalling and flow control |
| D. | only start signalling |
| Answer» C. both start & stop signalling and flow control | |
| Explanation: in asynchronous serial communication, the communication is not synchronized by clock signal. instead of a start and stop signaling and flow control method is followed. unlike asynchronous serial communication, in synchronous serial communication a clock signal is used for communication, so the start and stop method is not really required. | |
| 61. |
The physical layer is responsible for |
| A. | line coding |
| B. | channel coding |
| C. | modulation |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: the physical layer is | |
| 62. |
The physical layer translates logical communication requests from the into hardware specific operations. |
| A. | data link layer |
| B. | network layer |
| C. | trasnport layer |
| D. | application layer |
| Answer» A. data link layer | |
| Explanation: physical layer accepts data or information from the data link layer and converts it into hardware specific operations so as to transfer the message through physical cables. some examples of the cables used are optical fiber cables, twisted pair cables and co-axial cables. | |
| 63. |
A single channel is shared by multiple signals by |
| A. | analog modulation |
| B. | digital modulation |
| C. | multiplexing |
| D. | phase modulation |
| Answer» C. multiplexing | |
| Explanation: in communication and computer networks, the main goal is to share a scarce resource. this is done by multiplexing, where multiple analog or digital signals are combined into one signal over a shared medium. the multiple kinds of signals are designated by the transport layer which is the layer present on a higher level than the physical layer. | |
| 64. |
Wireless transmission of signals can be done via |
| A. | radio waves |
| B. | microwaves |
| C. | infrared |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: wireless transmission is carried out by radio waves, microwaves and ir waves. these waves range from 3 khz to above 300 ghz and are more suitable for wireless transmission. radio waves can penetrate through walls and are used in radio communications, microwaves and infrared (ir) waves cannot penetrate through walls and are used for satellite communications and device communications respectively. | |
| 65. |
In the digital communication system, signals in different frequency bands are |
| A. | orthogonal |
| B. | non orthogonal |
| C. | orthogonal & non orthogonal |
| D. | none of the mentioned |
| Answer» A. orthogonal | |
| Explanation: in digital communication system, signals from different frequency bands are orthogonal thus interference won’t occur. | |
| 66. |
Properties of impulse function are |
| A. | symmetry |
| B. | time scaling |
| C. | shifting |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the properties of impulse function are symmetry, time scaling and shifting. | |
| 67. |
Properties of Fourier transform are |
| A. | duality property |
| B. | time shifting property |
| C. | modulation property |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the properties of fourier transform are duality property, time scaling property, time shifting property, modulation property and many more. | |
| 68. |
A base-band signal can be up-converted using |
| A. | sine wave |
| B. | cosine wave |
| C. | filtering |
| D. | none of the mentioned |
| Answer» B. cosine wave | |
| Explanation: a base-band signal can be up- converted to band-pass filter by applying cosine wave. | |
| 69. |
A band-pass signal can be down-converted using |
| A. | sine wave |
| B. | cosine wave |
| C. | time delayed wave |
| D. | none of the mentioned |
| Answer» B. cosine wave | |
| Explanation: for down-conversion of a band-pass signal also cosine signal is used and multiplied with it. | |
| 70. |
In down-conversion multiplication with cosine wave is followed by |
| A. | low pass filter |
| B. | high pass filter |
| C. | bandpass filter |
| D. | bandstop filter |
| Answer» A. low pass filter | |
| Explanation: downconversion of bandpass signal includes multiplication with sine wave followed by low pass filtering. | |
| 71. |
Fourier transform of a signal gives the |
| A. | frequency content |
| B. | bandwidth |
| C. | frequency content & bandwidth |
| D. | none of the mentioned |
| Answer» C. frequency content & bandwidth | |
| Explanation: fourier transform of a signal give the frequency content and also determines the bandwidth of the signal. | |
| 72. |
Random things in a communication system are |
| A. | timing offset |
| B. | device frequency |
| C. | attenuation |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the random things in the communication system are noise in the channel, attenuation, fading, channel filtering, device frequency, phase and timing offset. | |
| 73. |
Which can be used for periodic and non periodic? |
| A. | fourier series |
| B. | fourier transforms |
| C. | fourier series & transforms |
| D. | none of the mentioned |
| Answer» B. fourier transforms | |
| Explanation: fourier series is limited to only periodic signals where as fourier transforms and laplace transforms can be used for both periodic and non periodic signals. | |
| 74. |
A band-pass signal has a Fourier transform equal to |
| A. | one |
| B. | zero |
| C. | infinity |
| D. | cannot be determined |
| Answer» B. zero | |
| Explanation: a band-pass signal has a fourier transform equal to zero for all value in both frequency and time domain. | |
| 75. |
A band-pass signal has |
| A. | dc component |
| B. | no dc component |
| C. | no side lobes |
| D. | cannot be determined |
| Answer» B. no dc component | |
| Explanation: a band-pass signal has no dc components and has fourier transform equal to zero. outside the band it will not be exactly zero. thus this results in presence of side lobes. | |
| 76. |
Which are orthonormal signal representation? |
| A. | sine and cosine at same frequency |
| B. | wavelets |
| C. | complex sinusoids at a different frequency |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: some of the common orthonormal signal representations are sine and cosine at the same frequency, fourier serier, sinc functions centered at sampling times, wavelets etc. | |
| 77. |
Constellation diagram is plotted in |
| A. | constellation space |
| B. | signal space |
| C. | orthogonal space |
| D. | boundary space |
| Answer» B. signal space | |
| Explanation: the constellation diagram is plotted in a space called as signal space. | |
| 78. |
Cumulative distributive function is |
| A. | non negative |
| B. | non decreasing |
| C. | non negative & decreasing |
| D. | none of the mentioned |
| Answer» C. non negative & decreasing | |
| Explanation: cumulative distribution function is non negative and non decreasing function. | |
| 79. |
Which are non negative functions? |
| A. | |
| B. | pmf |
| C. | pdf & pmf |
| D. | none of the mentioned |
| Answer» C. pdf & pmf | |
| Explanation: pdf, pmf and cdf are non negative functions. | |
| 80. |
Which of the following tasks is not done by data link layer? |
| A. | framing |
| B. | error control |
| C. | flow control |
| D. | channel coding |
| Answer» D. channel coding | |
| Explanation: channel coding is the function of physical layer. data link layer mainly deals with framing, error control and flow control. data link layer is the layer where the packets are encapsulated into frames. | |
| 81. |
Which sublayer of the data link layer performs data link functions that depend upon the type of medium? |
| A. | logical link control sublayer |
| B. | media access control sublayer |
| C. | network interface control sublayer |
| D. | error control sublayer |
| Answer» B. media access control sublayer | |
| Explanation: media access control (mac) deals with transmission of data packets to and from the network-interface card, and also to and from another remotely shared channel. | |
| 82. |
Header of a frame generally contains |
| A. | synchronization bytes |
| B. | addresses |
| C. | frame identifier |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: in a frame, the header is a part of the data that contains all the required information about the transmission of the file. it contains information like synchronization bytes, addresses, frame identifier etc. it also contains error control information for reducing the errors in the transmitted frames. | |
| 83. |
When 2 or more bits in a data unit has been changed during the transmission, the error is called |
| A. | random error |
| B. | burst error |
| C. | inverted error |
| D. | double error |
| Answer» B. burst error | |
| Explanation: when a single bit error occurs in a data, it is called single bit error. when more than a single bit of data is corrupted or has error, it is called burst error. if a single bit error occurs, the bit can be simply repaired by inverting it, but in case of a burst error, the sender has to send the frame again. | |
| 84. |
CRC stands for |
| A. | cyclic redundancy check |
| B. | code repeat check |
| C. | code redundancy check |
| D. | cyclic repeat check |
| Answer» A. cyclic redundancy check | |
| Explanation: cyclic redundancy check is a code that is added to a data which helps us to identify any error that occurred during the transmission of the data. crc is only able to detect errors, not correct them. crc is inserted in the frame trailer. | |
| 85. |
Which of the following is a data link protocol? |
| A. | ethernet |
| B. | point to point protocol |
| C. | hdlc |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: there are many data link layer protocols. some of them are sdlc (synchronous data link protocol), hdlc (high level data link control), slip (serial line interface protocol), ppp (point to point protocol) etc. these protocols are used to provide the logical link control function of the data link layer. | |
| 86. |
Which of the following is the multiple access protocol for channel access control? |
| A. | csma/cd |
| B. | csma/ca |
| C. | both csma/cd & csma/ca |
| D. | hdlc |
| Answer» C. both csma/cd & csma/ca | |
| Explanation: in csma/cd, it deals with detection of collision after collision has occurred, whereas csma/ca deals with preventing collision. csma/cd is abbreviation for carrier sensing multiple access/collision detection. csma/ca is abbreviation for carrier sensing multiple access/collision avoidance. these protocols are used for efficient multiple channel access. | |
| 87. |
The technique of temporarily delaying outgoing acknowledgements so that they can be hooked onto the next outgoing data frame is called |
| A. | piggybacking |
| B. | cyclic redundancy check |
| C. | fletcher’s checksum |
| D. | parity check |
| Answer» A. piggybacking | |
| Explanation: piggybacking is a technique in which the acknowledgment is temporarily delayed so as to be hooked with the next outgoing data frame. it saves a lot of channel bandwidth as in non-piggybacking system, some bandwidth is reserved for acknowledgement. | |
| 88. |
Automatic repeat request error management mechanism is provided by |
| A. | logical link control sublayer |
| B. | media access control sublayer |
| C. | network interface control sublayer |
| D. | application access control sublayer |
| Answer» A. logical link control sublayer | |
| Explanation: the logical link control is a sublayer of data link layer whose main function is to manage traffic, flow and error control. the automatic repeat request error management mechanism is provided by the llc when an error is found in the received frame at the receiver’s end to inform the sender to re-send the frame. | |
| 89. |
In layering, n layers provide service to |
| A. | n layer |
| B. | n-1 layer |
| C. | n+1 layer |
| D. | none of the mentioned |
| Answer» C. n+1 layer | |
| Explanation: in layering n layer provides service to n+1 layer and use the service provided by n-1 layer. | |
| 90. |
Which can be used as an intermediate device in between transmitter entity and receiver entity? |
| A. | ip router |
| B. | microwave router |
| C. | telephone switch |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| Explanation: ip router, microwave router and telephone switch can be used as an intermediate device between communication of two entities. | |
| 91. |
Which has comparatively high frequency component? |
| A. | sine wave |
| B. | cosine wave |
| C. | square wave |
| D. | none of the mentioned |
| Answer» C. square wave | |
| Explanation: square wave has comparatively high frequency component in them. | |
| 92. |
Which has continuous transmission? |
| A. | asynchronous |
| B. | synchronous |
| C. | asynchronous & synchronous |
| D. | none of the mentioned |
| Answer» B. synchronous | |
| Explanation: synchronous has continuous transmission where as asynchronous have sporadic transmission. | |
| 93. |
Which requires bit transitions? |
| A. | asynchronous |
| B. | synchronous |
| C. | asynchronous & synchronous |
| D. | none of the mentioned |
| Answer» B. synchronous | |
| Explanation: synchronous transmission needs bit transition. | |
| 94. |
In synchronous transmission, receiver must stay synchronous for |
| A. | 4 bits |
| B. | 8 bits |
| C. | 9 bits |
| D. | 16 bits |
| Answer» C. 9 bits | |
| Explanation: in synchronous transmission, receiver must stay synchronous for 9 bits. | |
| 95. |
How error detection and correction is done? |
| A. | by passing it through equalizer |
| B. | by passing it through filter |
| C. | by amplifying it |
| D. | by adding redundancy bits |
| Answer» D. by adding redundancy bits | |
| Explanation: error can be detected and corrected by adding additional information that is by adding redundancy bits. | |
| 96. |
Which is more efficient? |
| A. | parity check |
| B. | cyclic redundancy check |
| C. | parity & cyclic redundancy check |
| D. | none of the mentioned |
| Answer» B. cyclic redundancy check | |
| Explanation: cyclic redundancy check is more efficient than parity check. | |
| 97. |
Which can detect two bit errors? |
| A. | parity check |
| B. | cyclic redundancy check |
| C. | parity & cyclic redundancy check |
| D. | none of the mentioned |
| Answer» B. cyclic redundancy check | |
| Explanation: crc is more powerful and it can detect various kind of errors like 2 bit errors. | |
| 98. |
CRC uses |
| A. | multiplication |
| B. | binary division |
| C. | multiplication & binary division |
| D. | none of the mentioned |
| Answer» C. multiplication & binary division | |
| Explanation: crc uses more math like multiplication and binary division. | |
| 99. |
What is start frame delimeter (SFD) in ethernet frame? |
| A. | 10101010 |
| B. | 10101011 |
| C. | 00000000 |
| D. | 11111111 |
| Answer» B. 10101011 | |
| Explanation: the start frame delimiter is a 1 byte field in the ethernet frame that indicates that the preceding bits are the start of the frame. it is always set to 10101011. | |
| 100. |
MAC address is of |
| A. | 24 bits |
| B. | 36 bits |
| C. | 42 bits |
| D. | 48 bits |
| Answer» D. 48 bits | |
| Explanation: mac address is like a local address for the nic that is used to make a local ethernet (or wifi) network function. it is of 48 bits. | |
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