Tuesday, 17 January 2017

UGC Net Computer Science Paper II Dec 13 Page 5 Solved

UGC Net Computer Science Paper II Dec 13 Page 5 Solved

UGC Net Computer Science Paper II Dec 13 Page 5 Solved

41. Active X controls are Pentium binary programs that can be embedded in
(A) Word pages
(B) URL pages
(C) Script pages
(D) Web pages
Answer D
Explanation :-

An ActiveX control is a component program object that can be re-used by many application programs within a computer or among computers in a network. The technology for creating ActiveX controls is part of Microsoft's overall ActiveX set of technologies, chief of which is the Component Object Model (COM). ActiveX controls can be downloaded as small programs or animations for Web pages, but they can also be used for any commonly-needed task by an application program in the latest Windows and Macintosh environments. In general, ActiveX controls replace the earlier OCX (Object Linking and Embedding custom controls). An ActiveX control is roughly equivalent in concept and implementation to the Java applet.

42. Match the following :
                      List – I                                      List – II
a. Wireless Application Environment           i. HTTP
b. Wireless Transaction Protocol                  ii. IP
c. Wireless Datagram Protocol                     iii. Scripts
d. Wireless                                                    iv. UDP
Codes :
       a b c d
(A) ii iv i iii
(B) iv iii ii i
(C) iv iii i ii
(D) iii i iv ii
Answer D

43. Which of the following is widely used inside the telephone system for long-haul data traffic ?
(C) Frame Relay
Answer D
Explanation :-

     Asynchronous transfer mode (ATM) is, according to the ATM Forum, "a telecommunications concept defined by ANSI and ITU (formerly CCITT) standards for carriage of a complete range of user traffic, including voice, data, and video signals".[1] ATM was developed to meet the needs of the Broadband Integrated Services Digital Network, as defined in the late 1980s,[2] and designed to unify telecommunication and computer networks. It was designed for a network that must handle both traditional high-throughput data traffic (e.g., file transfers), and real-time, low-latency content such as voice and video. The reference model for ATM approximately maps to the three lowest layers of the ISO-OSI reference model: network layer, data link layer, and physical layer.[3] ATM is a core protocol used over the SONET/SDH backbone of the public switched telephone network (PSTN) and Integrated Services Digital Network (ISDN), but its use is declining in favour of all IP.

     ATM provides functionality that is similar to both circuit switching and packet switching networks: ATM uses asynchronous time-division multiplexing,[4][5] and encodes data into small, fixed-sized packets (ISO-OSI frames) called cells. This differs from approaches such as the Internet Protocol or Ethernet that use variable sized packets and frames. ATM uses a connection-oriented model in which a virtual circuit must be established between two endpoints before the actual data exchange begins.[5] These virtual circuits may be “permanent”, i.e. dedicated connections that are usually preconfigured by the service provider, or “switched”, i.e. set up on a per-call basis using signalling and disconnected when the call is terminated.
44. The document standards for EDI were first developed by large business house during the 1970s and are now under the control of the following standard organisation :
Answer B
Explanation :-
ANSI (American National Standards Institute) is the primary organization for fostering the development of technology standards in the United States. ANSI works with industry groups and is the U.S. member of the International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC).

45. Electronic Data Interchange Software consists of the following four layers :
(A) Business application, Internal format conversion, Network translator, EDI envelope
(B) Business application, Internal format conversion, EDI translator, EDI envelope
(C) Application layer, Transport layer, EDI translator, EDI envelope
(D) Application layer, Transport layer, IP layer, EDI envelope
Answer B
Explanation :-
Electronic data interchange (EDI) is an electronic communication method that provides standards for exchanging data via any electronic means. By adhering to the same standard, two different companies or organizations, even in two different countries, can electronically exchange documents (such as purchase orders, invoices, shipping notices, and many others). EDI has existed for more than 30 years, and there are many EDI standards (including X12, EDIFACT, ODETTE, etc.), some of which address the needs of specific industries or regions. It also refers specifically to a family of standards. In 1996, the National Institute of Standards and Technology defined electronic data interchange as "the computer-to-computer interchange of strictly formatted messages that represent documents other than monetary instruments. EDI implies a sequence of messages between two parties, either of whom may serve as originator or recipient. The formatted data representing the documents may be transmitted from originator to recipient via telecommunications or physically transported on electronic storage media." It distinguishes mere electronic communication or data exchange, specifying that "in EDI, the usual processing of received messages is by computer only. Human intervention in the processing of a received message is typically intended only for error conditions, for quality review, and for special situations. For example, the transmission of binary or textual data is not EDI as defined here unless the data are treated as one or more data elements of an EDI message and are not normally intended for human interpretation as part of online data processing. EDI can be formally defined as the transfer of structured data, by agreed message standards, from one computer system to another without human intervention.

46. Consider a preemptive priority based scheduling algorithm based on dynamically changing priority.Larger priority number implies higher priority. When the process is waiting for CPU in the ready queue (but not yet started execution), its priority changes at a rate a = 2. When it starts running, its priority changes at a rate b = 1. All the processes are assigned priority value 0 when they
enter ready queue. Assume that the following processes want to execute : 
Process ID               Arrival Time            Service Time
P1                                      0                               4
P2                                      1                               1
P3                                      2                               2
P4                                      3                               1

The time quantum q = 1. When two processes want to join ready queue simultaneously, the process which has not executed recently is given priority. The finish time of processes P1, P2, P3 and P4 will respectively be
(A) 4, 5, 7 and 8
(B) 8, 2, 7 and 5
(C) 2, 5, 7 and 8
(D) 8, 2, 5 and 7
Answer B
Explanation :-
T    EP   Priority After T
00  P1   P1[0]  P2[-]   P3[-]   P4[-]
01  P2   P1[1]  P2[0]  P3[-]   P4[-]
02  P1   P1[1]  P2[X]  P3[2]  P4[-] ........P2 completed at 2
03  P3   P1[2]  P2[X]  P3[2]  P4[2]
04  P4   P1[3]  P2[X]  P3[3]  P4[2]
05  P1   P1[3]  P2[X]  P3[4]  P4[X] .......P4 completed at 5
06  P3   P1[4]  P2[X]  P3[4]  P4[X]
07  P1   P1[4]  P2[X]  P3[X]  P4[X] .......P3 completed at 7
08  --     P1[X]  P2[X]  P3[X]  P4[X] .......P1 completed at 8

Read more: http://www.netcomputerscience.com
47. The virtual address generated by a CPU is 32 bits. The Translation Look-aside Buffer (TLB) can hold total 64 page table entries and a 4-way set associative (i.e. with 4-cache lines in the set). The page size is 4 KB. The minimum size of TLB tag is
(A) 12 bits
(B) 15 bits
(C) 16 bits
(D) 20 bits
Answer C
Explanation :-

VirtualAddress = 32 bits
PageSize = 4KB = 12 bits
therefore : VPNTag = 20 bits, OffsetTag = 12 bits
TLBEntryLength = VPNTag = 20 bits
TotalTLBEntries = 64,
4-way implies 64/ 4 = 16 sets = 4 bits
therefore : TLBIndex = 4 bits
TLBTag = TLBEntryLength - TLBIndex = 20 - 4 = 16 bits

Read more: http://www.netcomputerscience.com

48. Consider a disk queue with request for input/output to block on cylinders 98, 183, 37, 122, 14, 124, 65, 67 in that order. Assume that disk head is initially positioned at cylinder 53 and moving towards cylinder number 0. The total number of head movements using Shortest Seek Time
First (SSTF) and SCAN algorithms are respectively
(A) 236 and 252 cylinders
(B) 640 and 236 cylinders
(C) 235 and 640 cylinders
(D) 235 and 252 cylinders
Answer A
Explanation :-
Acc to SCAN   53 to 37 then to 14 and then to 0 (16+23+14=53) now direction will be reversed so 0 o 65 then to 67 then to 98,122,124,183   ( 65+2+31+24+2+59=183)total head movements=183+53=236

Acc to SSTF  53 to 65 then to 67 then 37 ,14,98,122,124,183 (so head movement= 12+2+30+23+84+24+2+59=236)
49. How much space will be required to store the bit map of a 1.3 GB disk with 512 bytes block size ?
(A) 332.8 KB
(B) 83.6 KB
(C) 266.2 KB
(D) 256.6 KB
Answer A
Explanation :-
block size=29bytes (512 bytes)
disk size=1.3x230bytes (1.3 GB)
n=1.3x230/29=1.3x221 bits=1.3x210x28x23 bits=1.3x28 Kilo Bytes=332.8

50. Linux operating system uses
(A) Affinity Scheduling
(B) Fair Preemptive Scheduling
(C) Hand Shaking
(D) Highest Penalty Ratio Next
Answer B
Explanation :-
Fair scheduling is a method of assigning resources to jobs such that all jobs get, on average, an equal share of resources over time. When there is a single job running, that job uses the entire cluster. When other jobs are submitted, tasks slots that free up are assigned to the new jobs, so that each job gets roughly the same amount of CPU time. Unlike the default Hadoop scheduler, which forms a queue of jobs, this lets short jobs finish in reasonable time while not starving long jobs. It is also an easy way to share a cluster between multiple of users. Fair sharing can also work with job priorities - the priorities are used as weights to determine the fraction of total compute time that each job gets.