Tuesday, 27 December 2016

UGC Net Computer Science Paper II Dec 12,Page 3 (Solve)

GC Net Computer Science Paper II Dec 12

21. Which API is used to draw a circle ?
(A) Circle ( )
(B) Ellipse ( )
(C) Round Rect ( )
(D) Pie ( )
Answer B
Explanation : In mathematics, an ellipse is a curve in a plane surrounding two focal points such that the sum of the distances to the two focal points is constant for every point on the curve. As such, it is a generalization of a circle.
22. In DML, RECONNCT command
cannot be used with
(A) OPTIONAL Set
(B) FIXED Set
(C) MANDATOR Set
(D) All of the above
Answer B
Explanation : The RECONNECT command can be used with both OPTIONAL and MANDATORY sets, but not with FIXED sets. The RECONNECT command moves a member record from one set instance to another set instance of the same set type. It cannot be used with FIXED sets because a member record cannot be moved from one set instance to another under the FIXED constraint.

23. Coaxial cables are categorized by Radio Government rating are adapted for specialized functions. Category RG-59 with impedance 75 ᘯ used for
(A) Cable TV
(B) Ethernet
(C) Thin Ethernet
(D) Thick Ethernet
Answer A
Explanation : RG59 cable has been around for a long time. This cable used to be what most people used for their cable TV connection. However, modern signal requirements have made this cable less popular in the last few years. RG 59 has a smaller conductor than RG 6, which means that it can’t achieve the same signal quality as RG 6. The way its shielding is designed also means that it doesn’t keep Gigahertz level signals inside the conductor very well. This is why RG 59 probably isn’t a good choice for your TV or internet connection.

RG 59 Siamese Coaxial Cable RG 59 is good for lower frequency signals (anything under about 50 MHz). That makes it a good choice for a closed circuit television (CCTV) video surveillance system.

24. RAD stands for ______.
(A) Rapid and Design
(B) Rapid Aided Development
(C) Rapid Application Development
(D) Rapid Application Design
Answer C
Explanation : Rapid application development (RAD) is a software development methodology that uses minimal planning in favor of rapid prototyping. A prototype is a working model that is functionally equivalent to a component of the product.

In RAD model the functional modules are developed in parallel as prototypes and are integrated to make the complete product for faster product delivery.

Since there is no detailed preplanning, it makes it easier to incorporate the changes within the development process. RAD projects follow iterative and incremental model and have small teams comprising of developers, domain experts, customer representatives and other IT resources working progressively on their component or prototype.

25. Suppose that someone starts with a chain letter. Each person who receives the letter is asked to send it on to 4 other people. Some people do this,while some do not send any letter. How many people have seen the letter,including the first person, if no one receives more than one letter and if the
chain letter ends after there have been 100 people who read it but did not send it out ? Also find how many people sent out the letter ?
(A) 122 & 22
(B) 111 & 11
(C) 133 & 33
(D) 144 & 44
Answer C

26. A hash function f defined as f (key) = key mod 13, with linear probing is used to insert keys 55, 58, 68, 91, 27, 145. What will be the location of 79 ?
(A) 1
(B) 2
(C) 3
(D) 4
Answer C
Explanation : Linear probing is a scheme in computer programming for resolving collisions in hash tables, data structures for maintaining a collection of key–value pairs and looking up the value associated with a given key. It was invented in 1954 by Gene Amdahl, Elaine M. McGraw, and Arthur Samuel and first analyzed in 1963 by Donald Knuth.

Along with quadratic probing and double hashing, linear probing is a form of open addressing. In these schemes, each cell of a hash table stores a single key–value pair. When the hash function causes a collision by mapping a new key to a cell of the hash table that is already occupied by another key, linear probing searches the table for the closest following free location and inserts the new key there. 

55 mod13 is 3. 3 rd slot is given to 55.Occupied slot is(3)
58 mod 13 is 6 . 6th slot is given to 58.Ocuppied slots are (3,6)
68 mod 13 is 3 . which is preoccupied hence next free slot 4 is allotted. Occupied slots are (3,4,6).
91 mod 13 is 0. 0th slot is given to 91. Occupied slots are (0,3,4,6)
27 mod 13 is 1. 1st slot is given to 27. Occupied slots are (0,1,3,4,6)
145 mod 13 is 2. 2nd slot is given to 145. Occupied slots are (0,1,2,3,4,6)
79 mod 13 is 1. 1st slot is already occupied and searches for the next free slot, that is 5. 5 th slot is allotted to 79

27. Which of the following is true while converting CFG to LL(I) grammar ?
(A) Remove left recursion alone
(B) Factoring grammar alone
(C) Both of the above
(D) None of the above
Answer C

28. Identify the Risk factors which are associated with Electronic payment system.
(A) Fraudulent use of Credit Cards.
(B) Sending Credit Card details over internet.
(C) Remote storage of Credit Card details.
(D) All of the above
Answer D

Explanation :

Fraudulent use of Credit Cards.

 Credit card fraud is a wide-ranging term for theft and fraud committed using or involving a payment card, such as a credit card or debit card, as a fraudulent source of funds in a transaction.The purpose may be to obtain goods without paying, or to obtain unauthorized funds from an account. Credit card fraud is also an adjunct to identity theft.In 1999, out of 12 billion transactions made annually, approximately 10 million—or one out of every 1200 transactions—turned out to be fraudulent.

Sending Credit Card details over internet.

Security experts unanimously agree a garden-variety, encrypted email is a very insecure way to send sensitive information. Email can be hacked, spoofed and eavesdropped.Unsecured email offers crooks four points of exposure -- your own computer, your email server, your recipient's email server, and your recipient's computer -- making it one of the riskiest ways to send credit card information.Even if you are submitting the message through a secure connection, if either computer is infected with a virus or other malware, it leaves the door open to hackers.

Remote storage of Credit Card details.

Remote storage of Credit Card details. is not secure because data can be unauthorized access remotely.

29. Which of the following are two special functions that are meant for handling exception, that occur during exception handling itself ?
(A) Void terminate ( ) and Void unexpected ( )
(B) Non void terminate ( ) and void unexpected ( )
(C) Void terminate ( ) and non void unexpected ( )
(D) Non void terminate ( ) and non void unexpected ( )
Answer A
Explanation :When a run time error occur then program closed abnormally so first termination is require and unexpected termination must be shown for error handling.

30. Which of the following memory allocation scheme suffers from external fragmentation ?
(A) Segmentation
(B) Pure demand paging
(C) Swapping
(D) Paging

Answer A
Explanation :

Memory Allocation is a particular instance of the general dynamic storage allocation problem, which concerns how to satisfy a request of size n from a list of free holes. There are many solutions to this problem. The first-fit, best-fit, and worst-fit strategies are the ones most commonly used to select a free hole from the set of available holes.


This procedure is a particular instance of the general dynamic storage allocation problem, which concerns how to satisfy a request of size n from a list of free holes. There are many solutions to this problem. The first-fit, best-fit, and worst-fit strategies are the ones most commonly used to select a free hole from the set of available holes.

  • First fit. Allocate the first hole that is big enough. Searching can start either at the beginning of the set of holes or where the previous first-fit search ended. We can stop searching as soon as we find a free hole that is large enough.
  • Best fit. Allocate the smallest hole that is big enough. We must search the entire list, unless the list is ordered by size. This strategy produces the smallest leftover hole.
  • Worst fit. Allocate the largest hole. Again, we must search the entire list, unless it is sorted by size. This strategy produces the largest leftover hole,which may be more useful than the smaller leftover hole from a best-fit approach.
Both the first-fit and best-fit strategies for memory allocation suffer from external fragmentation