UGC NET Paper 2 Computer Science – July 2018 – Question Paper with Answer Key

The definitions in an XML document are said to be __________ when the tagging system and definitions in the DTD are all in compliance.

Consider the JavaScript code:

var y = "12";
function f() {
    var y = "6";
    alert(this.y);
    function g() { alert(y); }
    g();
}
f();

If M is the number of alert dialog boxes generated by this code and D1, D2, …, DM are the contents displayed in each, then:

What is the output of the following Java program?

class simple {
    public static void main(String[] args) {
        simple obj = new simple();
        obj.start();
    }
    void start() {
        long[] P = {3, 4, 5};
        long[] Q = method(P);
        System.out.print(P[0] + P[1] + P[2] + ":");
        System.out.print(Q[0] + Q[1] + Q[2]);
    }
    long[] method(long[] R) {
        R[1] = 7;
        return R;
    }
} // end of class

What is the output of the following C program? (Assume little-endian representation, with the least significant byte at the lowest address, and a two-byte short int.)

#include <stdio.h>
int main()
{
    union saving {
        short int one;
        char two[2];
    };
    union saving m;
    m.two[0] = 5;
    m.two[1] = 2;
    printf("%d, %d, %d\n", m.two[0], m.two[1], m.one);
}

Given below are three implementations of swap() in C++:

(a) void swap(int a, int b) { int temp; temp = a; a = b; b = temp; }  called as swap(p, q);
(b) void swap(int &a, int &b) { int temp; temp = a; a = b; b = temp; }  called as swap(p, q);
(c) void swap(int *a, int *b) { int *temp; temp = a; a = b; b = temp; }  called as swap(&p, &q);

with int p = 0, q = 1 in main(). Which of these would actually swap the contents of p and q?

In Java, which of the following statements is/are True ?

S1 : The ‘final’ keyword applied to a class definition prevents the class from being extended through derivation.

S2 : A class can only inherit one class but can implement multiple interfaces.

S3 : Java permits a class to replace the implementation of a method that it has inherited. It is called method overloading.

Which of the following statements is/are True ? P : C programming language has a weak type system with static types. Q : Java programming language has a strong type system with static types.

A graphic display system has a frame buffer that is 640 pixels wide, 480 pixels high and 1 bit of color depth. If the access time for each pixel on the average is 200 nanoseconds, then the refresh rate of this frame buffer is approximately :

Which of the following statements is/are True regarding the solution to the visibility problem in 3D graphics ?

S1 : The Painter’s algorithm sorts polygons by depth and then paints (scan - converts) each Polygon on to the screen starting with the most nearest polygon.

S2 : Backface Culling refers to eliminating geometry with backfacing normals.

Consider the matrix M = [2 0 2; 0 1 1; 0 0 1] representing a set of planar (2D) geometric transformations in homogeneous coordinates. Which of the following statements about M is true?

For a software system P: estimated size 33,480 LOC; average productivity 620 LOC per person-month; 6 developers; average salary ₹50,000 per month. If E, D and C are the estimated effort (person-months), development time (months) and cost (₹ lakh), then (E, D, C) =

Match the following in Software Engineering :

A software system crashed 20 times in the year 2017 and for each crash, it took 2 minutes to restart. Approximately, what was the software availability in that year ?

Match the 5 CMM Maturity levels/CMMI staged representations in List- I with their characterizations in List-II

The solution of the recurrence relation T(m) = T(3 m/4) + 1 is :

Consider the array A=<4, 1, 3, 2, 16, 9, 10, 14, 8, 7>. After building heap from the array A, the depth of the heap and the right child of max-heap are _________ and _________ respectively. (Root is at level 0).

A hash function h(key) = key mod 7 with linear probing is used to insert the keys 44, 45, 79, 55, 91, 18, 63 into a table indexed 0 to 6. What will be the location of key 18?

Which of the following algorithms solves the single-source shortest paths ?

A text is made up of the characters A, B, C, D, E each occurring with the probability 0.08, 0.40, 0.25, 0.15 and 0.12 respectively. The optimal coding technique will have the average length of :

A binary search tree in which every non-leaf node has non-empty left and right subtrees is called a strictly binary tree. Such a tree with 19 leaves :

Match the following with respect to algorithm paradigms :

The maximum number of comparisons needed to sort 9 items using radix sort is (assume each item is 5 digit octal number) :

A 5-ary tree is tree in which every internal node has exactly 5 children. The number of left nodes in such a tree with 8 internal nodes will be :

Consider a Boolean function of ‘n’ variables. The order of an algorithm that determines whether the Boolean function produces a output 1 is :

Two finite state machines are said to be equivalent if they :

The finite state machine given in figure below recognizes :

A pushdown automata behaves like a Turing machine when the number of auxiliary memory is :

Pushdown automata can recognize language generated by_________.

To obtain a string of n Terminals from a given Chomsky normal form grammar, the number of productions to be used is :

Consider the two grammars: G₁: S → SbS | a G₂: S → aB | ab, A → AAB | a, B → ABb | b Which of the following options is correct?

Context-sensitive language can be recognized by a :

The set A= { 0n1n2n | n= 1, 2, 3,..............} is an example of a grammar that is :

A bottom-up parser generates :

Consider the statements: S₁: There exists no algorithm for deciding whether any two Turing machines M₁ and M₂ accept the same language. S₂: The problem of determining whether a Turing machine halts on any input is undecidable. Which of the following options is correct?

A slotted ALOHA network transmits 200-bit frames using a shared channel with a 200 Kbps bandwidth. Find the throughput of the system, if the system (all stations put together) produces 250 frames per second :

The period of a signal is 100 ms. Its frequency is _________.

The dotted-decimal notation of the following IPV4 address in binary notation is _________.10000001 00001011 00001011 11101111

Which of the following statements are true ?

(a) Advanced Mobile Phone System (AMPS) is a second generation cellular phone system.

(b) IS - 95 is a second generation cellular phone system based on CDMA and DSSS.

(c) The Third generation cellular phone system will provide universal personnel communication.

Match the following symmetric block ciphers with corresponding block and key sizes :

Which of the following statements is/are true?

(a) Three broad categories of Networks are

(i) Circuit Switched Networks

(ii) Packet Switched Networks

(iii) Message Switched Networks

(b) Circuit Switched Network resources need not be reserved during the setup phase.

(c) In packet switching there is no resource allocation for packets.

In Challenge-Response authentication the claimant ________.

Decrypt the message “WTAAD” using the Caesar Cipher with key=15.

To guarantee correction of up to t errors, the minimum Hamming distance d in a block code min must be ________.

Encrypt the message "HELLO MY DEARZ" using a transposition cipher with key: plaintext positions 2 4 1 3 → ciphertext positions 1 2 3 4.

At a particular time of computation, the value of a counting semaphore is 10. Then 12 P operations and “x” V operations were performed on this semaphore. If the final value of semaphore is 7, x will be :

In a paged memory, the page hit ratio is 0.40. The time required to access a page in secondary memory is equal to 120 ns. The time required to access a page in primary memory is 15 ns. The average time required to access a page is ________.

In a multi-user operating system, 30 requests are made to use a particular resource per hour, on an average. The probability that no requests are made in 40 minutes, when arrival pattern is a poisson distribution, is ______.

Normally user programs are prevented from handling I/O directly by I/O instructions in them. For CPUs having explicit I/O instructions, such I/O protection is ensured by having the I/O instructions privileged. In a CPU with memory mapped I/O, there is no explicit I/O instruction. Which one of the following is true for a CPU with memory mapped I/O ?

Which UNIX/Linux command is used to make all files and sub-directories in the directory “progs” executable by all users ?

Which of the following statements are true ?

(a) External Fragmentation exists when there is enough total memory space to satisfy a request but the available space is contiguous.

(b) Memory Fragmentation can be internal as well as external.

(c) One solution to external Fragmentation is compaction.

Page information in memory is also called as Page Table. The essential contents in each entry of a page table is/are _________.

Consider a virtual page reference string 1, 2, 3, 2, 4, 2, 5, 2, 3, 4. Suppose LRU page replacement algorithm is implemented with 3 page frames in main memory. Then the number of page faults are_________.

Consider the following three processes, with arrival time and CPU burst time in milliseconds: P1 (arrival 0, burst 7), P2 (arrival 1, burst 4), P3 (arrival 2, burst 8). The Gantt chart for the preemptive SJF scheduling algorithm is

In which of the following scheduling criteria, context switching will never take place?

In RDBMS, which type of Join returns all rows that satisfy the join condition ?

Consider a relation book (title, price) which contains the titles and prices of different books. Assuming that no two books have the same price, what does the following SQL query list ? Select title from book as B where (select count (*) from book as T where T.price > B.price) < 7

In a Hierachical database, a hashing function is used to locate the ________.

Relations produced from E - R Model will always be in ________.

Consider the following schedules involving two transactions: S₁: r₁(X); r₁(Y); r₂(X); r₂(Y); w₂(Y); w₁(X) S₂: r₁(X); r₂(X); r₂(Y); w₂(Y); r₁(Y); w₁(X) Which one of the following statements is correct?

For a database relation R(a, b, c, d) where the domains of a, b, c and d include only atomic values, and only the following functional dependencies and those that can be inferred from them hold :

a → c

b → d The relation is in _________.

A many-to-one relationship exists from entity set r₁ to entity set r₂. If Pk(r) denotes the primary key of relation r, how is it represented using functional dependencies?

Database systems that store each relation in a separate operating system file may use the operating system's authorization scheme, instead of defining a special scheme themselves. In this case, which of the following is false?

Let R₁(a, b, c) and R₂(x, y, z) be relations in which a is a foreign key of R₁ referring to the primary key of R₂. Consider: (a) insert into R₁, (b) insert into R₂, (c) delete from R₁, (d) delete from R₂. Which is correct about the referential integrity constraint?

Consider a hash table of size seven, with starting index zero, and a hash function (7x+3) mod 4. Assuming the hash table is initially empty, which of the following is the contents of the table when the sequence 1, 3, 8, 10 is inserted into the table using closed hashing ? Here “__” denotes an empty location in the table.

In Artificial Intelligence (AI), an environment is uncertain if it is ________.

In Artificial Intelligence (AI), a simple reflex agent selects actions on the basis of_________.

In heuristic search algorithms in Artificial Intelligence (AI), if a collection of admissible h … … . h heuristics 1 m is available for a problem and none of them dominates any of the others, which should we choose?

Consider the following sentences about A* search:

(a) A* expands all nodes with f(n) < C*.

(b) A* expands no nodes with f(n) ≥ C*.

(c) Pruning is integral to A*. Here C* is the cost of the optimal solution path. Which is correct?

Consider a vocabulary with only four propositions A, B, C and D. How many models are there for the sentence B ∨ C?

Consider the following statements:

(a) False ⊨ True

(b) If α ⊨ (β ∧ γ) then α ⊨ β and α ⊨ γ. Which of the following is correct?

Consider the following English sentence : “Agra and Gwalior are both in India”. A student has written a logical sentence for the above English sentence in First-Order Logic using predicate In(x, y), which means x is in y, as follows : In(Agra, India) V In(Gwalior, India) Which one of the following is correct with respect to the above logical sentence ?

Consider the following two sentences :

(a) The planning graph data structure can be used to give a better heuristic for a planning problem.

(b) Dropping negative effects from every action schema in a planning problem results in a relaxed problem. Which of the following is correct with respect to the above sentences ?

A knowledge base contains just one sentence, ∃x AsHighAs (x, Everest). Consider the following two sentences obtained after applying existential instantiation.

(a) AsHighAs (Everest, Everest)

(b) AsHighAs (Kilimanjaro, Everest) Which of the following is correct with respect to the above sentences ?

Consider the set of all possible five-card poker hands dealt fairly from a standard deck of fifty- two cards. How many atomic events are there in the joint probability distribution ?

E is the number of edges in the graph and f is maximum flow in the graph. When the capacities are integers, the runtime of Ford-Fulberson algorithm is bounded by :

Which of the following statements is false about convex minimization problem ?

The following LPP: Maximize z = 100x₁ + 2x₂ + 5x₃ subject to 14x₁ + x₂ − 6x₃ + 3x₄ = 7, 32x₁ + x₂ − 12x₃ ≤ 10, 3x₁ − x₂ − x₃ ≤ 0, x₁, x₂, x₃, x₄ ≥ 0, has

Digital data from a sensor can fill 0 to 32 buffers. Let the sample space be S = {0, 1, 2, …, 32}, where j means j buffers are full, and p(i) = (33 − i)/561. Let A be the event that an even number of buffers are full. Then p(A) is

The equivalence of ¬∃x Q(x) is

If Aᵢ = {−i, …, −2, −1, 0, 1, 2, …, i}, then ⋃ᵢ₌₁^∞ Aᵢ is

Match the following in List - I and List - II, for a function f :

Which of the relations on {0, 1, 2, 3} is an equivalence relation ?

Which of the following is an equivalence relation on the set of all functions from Z to Z?

Which of the following statements is true?

CMOS is a Computer Chip on the motherboard, which is :

In RS flip-flop, the output of the flip-flop at the time (t+1) is the same as the output at time t, after the occurrence of a clock pulse if :

Match the terms in List - I with the options given in List - II :

What does the following logic diagram represent?

The hexadecimal equivalent of the binary integer number 110101101 is :

Perform the following operation for the binary equivalent of the decimal numbers (−14) + (−15) 10 10 The solution in 8 bit representation is :

Match the items in List - I and List - II :

Which of the following mapping is not used for mapping process in cache memory ?

Simplify the following using K-map : F(A,B,C,D) = 𝛴 (0,1,2,8,9,12,13) d(A,B,C,D) = 𝛴 (10, 11,14,15) d stands for don't care condition.

In 8085 microprocessor, what is the output of following program? LDA 8000 H MVI B, 30 H ADD B STA 8001H