UGC NET Paper 2 Computer Science – November 2020 – Question Paper with Answer Key

The number of positive integers not exceeding 100 that are either odd or the square of an integer is ____

How many ways are there to pack six copies of the same book into four identical boxes, where a box contains six books?

Which of the following pairs of propositions are not logically equivalent?

Maximize z = 2x₁ + 3x₂ subject to 2x₁ + x₂ ≤ 4, x₁ + 2x₂ ≤ 5, x₁, x₂ ≥ 0. The optimum value is

A machine has a byte-addressable main memory of 2¹⁶ bytes and a block size of 8 bytes. A direct-mapped cache with 32 lines is used. How many bits are in the tag, line and word fields of the address?

The following program is stored in the basic computer (locations in hex): 210 CLA; 211 ADD 217; 212 INC; 213 STA 217; 214 LDA 218; 215 CMA; 216 AND 217; 217 1234H; 218 9CE2H. What is the content of the accumulator after execution?

A non-pipeline system takes to process a task. The same task can be processed in six- segment pipeline with a clockcycle of 10ns. Determine approximately the speedup ratio of the pipeline for 500 tasks.

What is the radix of the numbers if the solutions of x² − 10x + 26 = 0 are x = 4 and x = 7?

With preconditions a > 1 and a < b (no overflow): int x = 0; int p = 1; while (p < b) { p = p * a; x = x + 1; } When the loop ends, x in terms of a and b is

In HTML, map > tag is used for

With 1-byte chars, 2-byte shorts, 4-byte ints and 8-byte doubles, each aligned to its size, no field reordering, and padding for alignment, how much space does this array use? struct { short s; char c; short t; char d; double r; int i; } A[10];

Consider the Java function: public static float f(long m, long n) { float result = (float)m / (float)n; if (m < 0 || n < 0) return 0.0f; else result -= f(m * 2, n * 3); return result; } Which value best approximates f(1, 3)?

The data node and name node in HADOOP are

Consider a relational schema S = (U, V , W, X, Y , Z) on which the following functional dependencies hold: {U → V , V W → X, Y → W, X → U} Which are the candidate keys among following options?

A machine has 3 page frames and 5 virtual pages. The reference string is A, B, C, D, A, B, E, A, B, C, D, E, B, A, B. If P and Q are the page faults with FIFO and LRU respectively, then (P, Q) =

Consider a single-level page table system, with the page table stored in the memory. If the hit 80% rate to TLB is , and it takes 15 nanoseconds to search the TLB, and 150 nanoseconds to access the main memory, then what is the effective memory access time, in nanoseconds?

Modifying the software by restructuring is called

A company can develop software in L₁ or L₂. L₂ needs three times the LOC of L₁, and the software must be maintained for 10 years. Man-years for development: LOC/1000 for both. Development cost per man-year: L₁ ₹70,000, L₂ ₹90,000. Maintenance per year: L₁ ₹1,00,000, L₂ ₹40,000. Total cost includes development and maintenance. For what LOC of L₁ are the costs equal?

A Software project was estimated at 864 Function Points. A six person team will be assigned to project consisting of a requirement gathering person, one designer, two programmers and two testers. The salary of the designer is ₹ 70,000 per month, requirement gatherer is ₹ 50,000 per month, programmer is ₹ 60,000 per month and a tester is ₹ 60,000 per month. Average productivity for the team is 12 FP per person month. Which of the following represents the projected cost of the project?

A complete -ary tree is a tree in which each n I node has children or no children. Let be the L number of internal nodes and be the number n L = 41 of leaves in a complete -ary tree. If , I = 10 n and , What is the value of ?

In a binary max heap containing numbers, the smallest element can be found in ____ time.

If algorithm A and another algorithm B take −− log (n) √n 2 and microseconds, respectively, to n solve a problem, then the largest size of a problem these algorithms can solve, respectively, in one second are ___ and _____

Let be a directed graph whose vertex set is the set of numbers from 1 to 100 . There is an i j edge from a vertex to a vertex if and only if j = i + 1 j = 3i either or . The minimum G number of edges in a path in from vertex 1 to vertex 100 is ____

Let L = L₁ ∩ L₂, where L₁ = {0ᵐ1ᵐ2 0ⁿ1ⁿ | m, n ≥ 0} and L₂ = {0ᵐ1ⁿ2ᵏ | m, n, k ≥ 0}. Then L is

Let 1 and 2 be languages over represented by the regular expressions (a∗ + b)∗ (a + b)∗ and respectively. Which of the following is true with respect to the two languages?

Which of the following statements is true?

Which of the following is not an intermediate code form?

Consider a code with only four valid code words: 0000000000,0000011111,1111100000, and 1111111111. This code has distance 5. If the code word arrived is 0000000111 then the original code word must be _____

Using RSA with p = 3, q = 11 and d = 7, find the value of e and encrypt the number 19.

Protocols in which the sender sends one frame and then waits for an acknowledgement before proceeding for next frame are called as ______

The period of a signal is . Then the frequency of this signal in kilohertz is ______

The process of removing details from a given state representation is called ______

Which of the following is NOT true in problem solving in artificial intelligence?

If f(x)=x is my friend, and p(x)=x is perfect, then the correct logical translation of the statement "some of my friends are not perfect" is:

What kind of clauses are available in conjunctive normal form?

Consider the following properties:

A. Reflexive

B. Antisymmetric

C. Symmetric A = {a, b, c, d, e, f, g} Let and R = {(a, a), (b, b), (c, d), (c, g), (d, g), (e, e), (f, f), (g, g)} be a relation on (A). Which of the following property (properties) is (are) satisfied by the relation (R) ?

Consider the argument with premise ∀x(P(x) ∨ Q(x)) and conclusion (∀x P(x)) ∧ (∀x Q(x)): (A) ∀x(P(x) ∨ Q(x)) premise; (B) P(c) ∨ Q(c) universal instantiation from A; (C) P(c) simplification from B; (D) ∀x P(x) universal generalization of C; (E) Q(c) simplification from B; (F) ∀x Q(x) universal generalization of E; (G) (∀x P(x)) ∧ (∀x Q(x)) conjunction of D and F.

Which of the following are applications of symbol table?

(A) Storage allocation

(B) Checking type compatability

(C) Suppressing duplicate error messages

Which simplified expressions are correct for F(A, B, C, D) = Σ(0, 1, 2, 3, 6, 12, 13, 14, 15)? (A) A′B′ + AB + A′C′D′ (B) A′B′ + AB + A′CD′ (C) A′B′ + AB + BC′D′ (D) A′B′ + AB + BCD′

Which of the following statements with respect to K-segment pipelining are true?

(A) Maximum speedup that a pipeline can provide is k theoretically.

(B) It is impossible to achieve maximum speedup k in k-segment pipeline.

(C) All segments in pipeline take same time in computation.

Which of the following statements with respect to multiprocessor system are true?

(A) Multiprocessor system is controlled by one operating system.

(B) In Multiprocessor system, multiple computers are connected by the means of communication lines.

(C) Multiprocessor system is classified as multiple instruction stream and multiple data stream system.

Which of the following statements regarding XML is/are True?

(A) XML is a set of tags designed to tell browsers how to display text and images in a web page.

(B) XML defines a syntax for representing data, but the meaning of data varies from application to application.

(C) <Letter>, <LETTER>, and <letter> are three different tags in XML.

In the context of 3D Computer graphics, which of the following statements is/are correct?

(A) Under perspective projection, each set of parallel lines in the object do not stay parallel in the image (except those that are parallel to the viewplane to start with).

(B) Applying a perspective transformation in the graphics pipeline to a vertex involves dividing by its ' (z) ' coordinate.

(C) Perspective transformation is a linear transformation.

Concerning phong shading and Gouraud shading in a 3D scene, which of the following statements are true?

(A) Gouraud shading requires more computation than phong shading.

(B) Gouraud shading linearly interpolates the color of an interior pixel from the color at the vertices.

(C) Phong shading interpolates over the normal vectors specified at the vertices.

In the context of concurrency control, a given pair of operations in a schedule is called conflict schedule if

(A) At least one of the operations is write operation.

(B) Both the operations are performed on the same data item.

(C) Both the operations are performed by different transactions.

(D) Both the operations are performed on different data items.

Software reliability is described with respect to

(A) Execution Time

(B) Calendar Time

(C) Clock Time

To create an object-behavioral model, the analyst performs the following steps:

(A) Evaluates all use-cases

(B) Builds state transition diagram for the system.

(C) Reviews the object behaviour model to verify accuracy and consistency

(D) Identifies events that do not derive the interaction sequence.

Which of the following is/are behavioral testing technique(s)?

(A) Equivalence Partitioning

(B) Graph-Based Teating Method

(C) Boundery Value Analysis

(D) Data flow Testing

(E) Loop Testing

The running time of an algorithm is O(g(n)) if and only if:

(A) its worst-case running time is O(g(n)) and its best-case running time is Ω(g(n)).

(B) its worst-case running time is Ω(g(n)) and its best-case running time is O(g(n)).

(C) O(g(n))=Ω(g(n)) (O= big O).

(D) o(g(n))∩ω(g(n)) is non-empty. (o= small o)

Choose the correct answer from the options given below:

(A) (A) only (B) (B) only

Consider the following statements:

(A) Any tree is 2-colorable

(B) A graph G has no cycles of even length if it is bipartite.

(C) A graph G is 2-colorable if it is bipartite.

(D) A graph G can be colored with d+1 colors if d is the maximum degree of any vertex in the graph G.

(E) A graph G can be colored with O(log∣v∣) colors if it has O(∣v∣) edges.

Which among the following statement(s) is (are) true?

(A) A hash function takes a message of arbitrary length and generates a fixed length code.

(B) A hash function takes a message of fixed length and generates a code of variable length.

(C) A hash function may give same hash value for distinct messages.

Let G1 and G2 be arbitrary context-free grammars and R an arbitrary regular language. Which problems are undecidable? (A) Is L(G1) = L(G2)? (B) Is L(G2) ⊆ L(G1)? (C) Is L(G1) = R?

Consider L1 = {a^(z²) | z is an integer}, L2 = {a^(2z) | z ≥ 0}, L3 = {ωω | ω ∈ {a, b}*}. Which of the languages is (are) regular?

Which of the following grammars is (are) ambiguous? (A) S → SS | aSb | bSa | λ (B) S → aSbS | bSaS | λ (C) S → aAB, A → bBb, B → A | λ, where λ denotes the empty string

Post office protocol (POP) is a message access protocol which is used to extract message for client. In this regard, which of the following are true?

(A) POP has two modes, Delete mode and keep

(B) In Delete mode, mail is deleted from mail box after each retrival

(C) In Delete mode, mail is deleted from mail box before each retrieval

(D) In keep mode, mail is deleted before retrival

(E) In keep mode, mail remains in mail box after retrival

Firewall is a device that filters access to the protected network from the outside network. Firewalls can filter the packets on the basis of

(A) Source IP Address

(B) Destination IP Address

(C) TCP Source Port

(D) UDP Source Port

(E) TCP Destination Port

Consider the statement: A person who is radical (R) is electable (E) if he/she is conservative (C), but otherwise is not electable. Which of these assertions are correct? (A) (R ∧ E) ⇔ C (B) R ⇒ (E ⇔ C) (C) R ⇒ ((C ⇒ E) ∨ ¬E) (D) (¬R ∨ ¬E ∨ C) ∧ (¬R ∨ ¬C ∨ E)

Which of the following statements are true? α β β

(A) A sentence entails another sentence if α is true in few worlds where is true.

(B) Forward chaining and backward chaining are very natural reasoning algorithms for knowledge bases in Horn form.

(C) Sound inference algorithms derive all sentences that are entailed.

(D) Propositional logic does not scale to environments of unbounded size.

Which of the following statements are true?

(A) Minimax search is breadth-first; it processes all the nodes at a level before moving to a node in next level.

(B) The effectiveness of the alpha-beta pruning is highly dependent on the order in which the states are examined.

(C) The alpha-beta search algorithm computes the same optimal moves as minimax algorithm.

(D) Optimal play in games of imperfact information does not require reasoning about the current and future belief states of each player.

Let R1 = {(1,1), (2,2), (3,3)} and R2 = {(1,1), (1,2), (1,3), (1,4)}. Match List I with List II. List I: A. R1 ∪ R2, B. R1 − R2, C. R1 ∩ R2, D. R2 − R1. List II: I. {(1,1), (1,2), (1,3), (1,4), (2,2), (3,3)}, II. {(1,1)}, III. {(1,2), (1,3), (1,4)}, IV. {(2,2), (3,3)}.

Match List I with List II. List I: A. Handshaking, B. Programmed I/O, C. Interrupt-initiated I/O, D. I/O processor. List II: I. I/O interface informs the CPU that the device is ready for transfer, II. Requires two control signals working in opposite directions, III. Has local memory and controls a large set of I/O devices, IV. Requires the CPU to check the I/O flag and perform the transfer.

Match List-I with List-II. List I gives matrices representing 2D transformations and List-II shows the corresponding transformation diagrams.

Match List I with List II.

Match List I (CMM levels) with List II. List I: A. INITIAL, B. REPEATABLE, C. DEFINED, D. MANAGED. List II: I. Process measurement, II. Process definition, III. Project management, IV. Ad hoc.

Match List I with List II. List I: A. Branch-and-bound, B. Steepest-ascent hill climbing, C. Constraint satisfaction, D. Means-end analysis. List II: I. Keeps track of all partial paths that can be candidates for further exploration, II. Detects the difference between the current state and the goal state, III. Discovers problem state(s) that satisfy a set of constraints, IV. Considers all moves from the current state and selects the best move.

Match List I with List II. List I: A. Topological sort of a DAG, B. Kruskal's MST algorithm, C. Bellman-Ford single-source shortest path, D. Floyd-Warshall all-pairs shortest path. List II: I. O(V + E), II. O(VE), III. θ(V + E), IV. θ(V³).

Match List I with List II (L_R regular, L_CF context-free, L_REC recursive, L_RE recursively enumerable). List I: A. Recursively enumerable language, B. Recursive language, C. Context-free language. List II: I. complement(L_REC) ∪ L_RE, II. complement(L_CF) ∪ L_REC, III. L_R* ∩ L_CF.

Match List I with List II. List I: A. Serial Line IP (SLIP), B. Border Gateway Protocol (BGP), C. User Datagram Protocol (UDP), D. Simple Network Management Protocol (SNMP). List II: I. Application layer, II. Transport layer, III. Data link layer, IV. Network layer.

Match List I with List II. List I: A. Greedy best-first search, B. A*, C. Recursive best-first search, D. SMA*. List II: I. Space complexity is O(d), where d is the depth of the deepest optimal solution, II. Incomplete even if the search space is finite, III. Optimal if the optimal solution is reachable; otherwise returns the best reachable solution, IV. Computation and space complexity are too high.

Find the lexicographic ordering of the bit strings 0 < 1 given below based on the ordering .

(A) 001

(B) 010

(C) 011

(D) 0001

(E) 0101

Choose the correct answer from the options given below:

Arrange the following types of machine in descending order of complexity.

(A) SISD

(B) MIMD

(C) SIMD

Choose the correct answer from the options given below:

Given below are different properties of 3D projections from A-D. Identify the correct order on the basis of property true of (i) a perspective projection only, (ii) an orthographic projection only, (iii) both orthographic and projective transformations and (iv) neither orthographic nor projective transformation, respectively.

(A) Straight lines are mapped to straight lines.

(B) Distances and angles are (in general) preserved.

(C) Far away objects appear the same size as closer ones.

(D) Requires homogeneous coordinates in order for it to be encoded into a linear transformation.

Choose the correct answer from the options given below:

Consider the undirected graph below:

Using Prim's algorithm to construct a minimum spanning tree starting with node a, which one of the following sequences of edges represents a possible order in which the edges would be added to construct the minimum spanning tree?

Consider the regular expressions r = a(b + a)*, s = a(a + b)⁺, t = aa*b. Which relation holds between the languages they generate?

Statement I: 5 divides n⁵ − n whenever n is a non-negative integer. Statement II: 6 divides n³ − n whenever n is a non-negative integer.

Given below are two statements:

Statement I : Hardwired control unit can be optimized to produce fast mode of operation.

Statement II : Indirect addressing mode needs two memory reference to fetch the operand. In the light of the above statements, choose the correct answer from the options given below

Given below are two statements:

Statement I : Bezier curves are curves that interpolate all of their control points.

Statement II : A cubic bezier curve has four control points. In the light of the above statements, choose the correct answer from the options given below

Given below are two statements: V V If two variables 1 and 2 are used for clustering, then consider the following k k = 3 statements for means clustering with V V

Statement I : If 1 and 2 have correlation of 1 the cluster centroid will be in straight line. V V

Statement II : If 1 and 2 have correlation of 0 the cluster centroid will be in straight line. In the light of the above statements, choose the correct answer from the options given below

Assuming fork() never fails, consider: P1: int main() { fork(); fork(); fork(); printf("Happy\n"); } and P2: int main() { fork(); printf("Happy\n"); fork(); fork(); printf("Happy\n"); }. Statement I: P1 displays "Happy" 8 times. Statement II: P2 displays "Happy" 12 times.

G T Let be a simple undirected graph, D be a DFS G T tree on , and B be the BFS tree on G. Consider the following statements. G

Statement I : No edge of is a cross with T respect to D (u, v) G u

Statement II : For every edge of , if is i v j T at depth and is at depth in B then |i − j| = 1 . In the light of the above statements, choose the correct answer from the options given below

Given below are two statements: L ∧ L = ϕ

Statement I : The problem "Is 1 2 ? " is L undecidable for context sensitive languages 1 L and 2. ∈

Statement II : The problem "Is W L?" is decidable W for context sensitive language L, (where is a string). In the light of the above statements, choose the correct answer from the options given below

Given below are two statements:

Statement I: The laws of nature put two fundamental limits on the data rate of a channel. The H.Nyquist limit restricts the number of independent samples per second to twice the bandwidth in a Noiseless channel.

Statement II: Shannon's major result about noised channel is that the maximum data rate of a channel whose bandwidth is HHz, and whose S signal-to-noise ratio is N is given by: S Maximum number of bits/sec= Hlog ( 1+ ) 2 N In the light of the above statements, choose the correct answer from the options given below

Given below are two statements:

Statement I: In Ceasar Cipher each letter of Plain text is replaced by another letter for encryption.

Statement II: The Diffie-Hellman algorithm is used for the exchange of secret keys. In the light of the above statements, choose the correct answer from the options given below

Given below are two statements:

Statement I: A genetic algorithm is a stochastic hill-climbing search in which a large population of states is maintained.

Statement II: In nondeterministic environments, agents can apply AND-OR search to generate contingent plans that reach the goal regardless of which outcomes occur during execution. In the light of the above statements, choose the correct answer from the options given below

If T is the capacity of a track in bytes, and S is the capacity of each surface in bytes, then (T, S)= _____

What is the capacity of the disk, in bytes?

Given below are two statements:

Statement I: The disk has a total number of 2000 cylinders.

Statement II: 51200 bytes is not a valid block size for the disk. In the light of the above statements, choose the correct answer from the options given below:

If the disk platters rotate at 5400 rpm (revolutions per minute), then approximately what is the maximum rotational delay?

If one track of data can be transferred per revolution, then what is the data transfer rate?

On the basis of above given table structures, retrieve the distinct employee ID (EMPID) of all employees of university who are working on project No.20, 30 and 40.

Given below are two statements to find the sum of salaries of all employees of the English department as well as the maximum, minimum and average salary in English department. STATEMENT I ： SELECT SUM (SALARY), MAX (SALARY), MIN (SALARY), AVG (SALARY) FROM EMPLOYEE, DEPARTMENT WHERE DEPTNO=DID AND DNAME='ENGLISH'; STATEMENT II: SELECT SUM (SALARY), MAX (SALARY), MIN (SALARY), AVG (SALARY) FROM EMPLOYEE, DEPARTMENT WHERE DNAME='ENGLISH'; In the light of the above statements, choose the correct answer from the options given below

Which of the following query/queries

return the employee ID and name of
employees whose salary is greater than

the salary of all employees in department number 20 of university? Order results by employee ID (refer to table structures given above).

(A) SELECT EID, NAME FROM EMPLOYEE WHERE SALARY>(SELECT SALARY FROM EMPLOYEE WHERE DEPTNO=20)

ORDER BY EID;
(B) SELECT EID, NAME
FROM EMPLOYEE WHERE SALARY>
(SELECT SALARY FROM EMPLOYEE
WHERE DEPTNO =20 );
(C) SELECT EID, NAME
FROM EMPLOYEE
WHERE SALARY>ALL(SELECT SALARY
FROM EMPLOYEE WHERE DEPTNO =20)
ORDER BY EID

In reference to the above given table

structures, which of the following
query/queries will drop the 'SALARY'
column from 'EMPLOYEE' table?
(A) ALTER TABLE EMPLOYEE DROP
SALARY CASCADE;
(B) ALTER TABLE EMPLOYEE DROP
SALARY RESTRICT;
(C) ALTER EMPLOYEE DROP SALARY;

Refer table, structures given above. The university decided to give all employees in the 'SCIENCE' department a 20% rise in salary. Which of the following query/queries will compute the above results?

(A) UPDATE EMPLOYEE SET SALARY = SALARY * 1.20 WHERE DEPT NO. IN (SELECT DID FROM DEPARTMENT WHERE DNAME='SCIENCE');

(B) UPDATE TABLE EMPLOYEE SET SALARY = SALARY * 1.20 WHERE DNAME='SCIENCE';

(C) ALTER TABLE EMPLOYEE SET SALARY=SALARY * 1.20 WHERE DEPTNO. IN (SELECT DNAME FROM DEPARTMENT WHERE DNAME = 'SCIENCE')