CS601 - Data Communication	Home Page	Mcqs	Q & A	Video	Online Test	Foram
ID Qus A B C D Ans 1 In a _______ connection, more than two devices can share a single link Point-to-point Primary Multipoint Secondary C 2 Communication between a computer and a keyboard involves ______________transmission Communication between a computer and a keyboard involves ______________ transmission Half-duplex Simplex Automatic C 3 In a network with 25 computers, which topology would require the most extensive cabling? Star Mesh Bus Ring B 4 Which topology requires a central controller or hub? Star Mesh Bus Ring A 5 The _______ is the physical path over which a message travels Protocol Medium Signal All of the above B 6 Which organization has authority over interstate and international commerce in the communications field? ITU-T IEEE ISO FCC D 7 The information to be communicated in a data communications system is the ________ Medium Protocol Transmission Message D 8 Frequency of failure and network recovery time after a failure are measures of the _______ of a network Performance Security Reliability Feasibility C 9 In _______ transmission, the channel capacity is shared by both communicating devices at all times Full-duplex Simplex Half-duplex Half-Simplex A 10 An unauthorized user is a network _______ issue Performance Reliability Security All of the above C 11 Which topology requires a multipoint connection? Mesh Star Ring Bus D 12 A television broadcast is an example of _______ transmission Half-duplex Full-duplex Simplex Automatic C 13 A _______ connection provides a dedicated link between two devices Multipoint Point-to-Point Primary Secondary B 14 A cable break in a _______ topology stops all transmission Mesh Star Primary Bus B 15 The _______ layer changes bits into electromagnetic signals Physical Transport None of the above Data link A 16 The physical layer is concerned with the transmission of _______ over the physical medium Programs Protocols Bits Dialogs C 17 Mail services are available to network users through the _______ layer Data link Physical Application Transport C 18 As the data packet moves from the lower to the upper layers, headers are _______ Added Rearranged Modified Subtracted D 19 As the data packet moves from the upper to the lower layers, headers are _______ Removed Added Rearranged Modified B 20 The _______ layer lies between the network layer and the application layer Data link Physical Transport None of the above C 21 Layer 2 lies between the physical layer and the _______ layer Data link Network Transport None of the above B 22 When data are transmitted from device A to device B, the header from A's layer 4 is read by B's _______ layer Application Physical Transport None of the above C 23 Which layer functions as a liaison between user support layers and network support layers? Network layer Transport layer Physical layer Application layer B 24 What is the main function of the transport layer? Process-to-process delivery Node-to-node delivery Synchronization Updating and maintenance of routing tables A 25 Which of the following is an application layer service? Remote log-in File transfer and access Mail service All the above D 26 The Internet model consists of _______ layers 3 5 7 8 B 27 The process-to-process delivery of the entire message is the responsibility of the _______ layer Physical Network Transport Application C 28 The _______ layer is the layer closest to the transmission medium Network Physical Data link Transport B 29 Before data can be transmitted, they must be transformed to ________ Electromagnetic signals Periodic signals Aperiodic signals Low-frequency sine waves A 30 When one of the components of a signal has a frequency of zero, the average amplitude of the signal ________ Is less than zero Is greater than zero Is zero (a) or (b) B 1 2 3 4 5 6 7 8 9 10 ...