GATE 2015 CS (Set 3)

All 65 questions of GATE 2015 CS (Set 3)

Question text and figures as in the official paper, with the answer from the official key. Worked solutions for every question are in your report after you take the paper as a 3-hour test.

Q1 · General Aptitude · MCQ · 1 mark

Extreme focus on syllabus and studying for tests has become such a dominant concern of Indian students that they close their minds to anything __________ to the requirements of the exam.

  • (A)
    related
  • (B)
    extraneous
  • (C)
    outside
  • (D)
    useful

Answer (official key): B

Worked solution: in your report after you take this paper.

Q2 · General Aptitude · MCQ · 1 mark

The Tamil version of __________ John Abraham-starrer Madras Cafe __________ cleared by the Censor Board with no cuts last week, but the film's distributors __________ no takers among the exhibitors for a release in Tamil Nadu __________ this Friday.

  • (A)
    Mr., was, found, on
  • (B)
    a, was, found, at
  • (C)
    the, was, found, on
  • (D)
    a, being, find at

Answer (official key): C

Worked solution: in your report after you take this paper.

Q3 · General Aptitude · MCQ · 1 mark

A function f(x)f(x) is linear and has a value of 29 at x=−2x=-2 and 39 at x=3x=3. Find its value at x=5x=5.

  • (A)
    59
  • (B)
    45
  • (C)
    43
  • (D)
    35

Answer (official key): C

Worked solution: in your report after you take this paper.

Q4 · General Aptitude · MCQ · 1 mark

If ROAD is written as URDG, then SWAN should be written as:

  • (A)
    VXDQ
  • (B)
    VZDQ
  • (C)
    VZDP
  • (D)
    UXDQ

Answer (official key): B

Worked solution: in your report after you take this paper.

Q5 · General Aptitude · MCQ · 1 mark

Select the pair that best expresses a relationship similar to that expressed in the pair:

Children : Pediatrician

  • (A)
    Adult : Orthopaedist
  • (B)
    Females : Gynaecologist
  • (C)
    Kidney : Nephrologist
  • (D)
    Skin : Dermatologist

Answer (official key): B

Worked solution: in your report after you take this paper.

Q6 · General Aptitude · MCQ · 2 marks

Alexander turned his attention towards India, since he had conquered Persia.

Which one of the statements below is logically valid and can be inferred from the above sentence?

  • (A)
    Alexander would not have turned his attention towards India had he not conquered Persia.
  • (B)
    Alexander was not ready to rest on his laurels, and wanted to march to India.
  • (C)
    Alexander was completely in control of his army and could command it to move towards India.
  • (D)
    Since Alexander's kingdom extended to Indian borders after the conquest of Persia, he was keen to move further.

Answer (official key): A

Read the worked solution

Q7 · General Aptitude · MCQ · 2 marks

Most experts feel that in spite of possessing all the technical skills required to be a batsman of the highest order, he is unlikely to be so due to lack of requisite temperament. He was guilty of throwing away his wicket several times after working hard to lay a strong foundation. His critics pointed out that until he addressed this problem, success at the highest level will continue to elude him.

Which of the statement(s) below is/are logically valid and can be inferred from the above passage?

(i) He was already a successful batsman at the highest level.
(ii) He has to improve his temperament in order to become a great batsman.
(iii) He failed to make many of his good starts count.
(iv) Improving his technical skills will guarantee success.

  • (A)
    (iii) and (iv)
  • (B)
    (ii) and (iii)
  • (C)
    (i), (ii) and (iii)
  • (D)
    (ii) only

Answer (official key): B

Read the worked solution

Q8 · General Aptitude · MCQ · 2 marks

The head of a newly formed government desires to appoint five of the six selected members P, Q, R, S, T, and U to portfolios of Home, Power, Defense, Telecom, and Finance. U does not want any portfolio if S gets one of the five. R wants either Home or Finance or no portfolio. Q says that if S gets either Power or Telecom, then she must get the other one. T insists on a portfolio if P gets one.

Which is the valid distribution of portfolios?

  • (A)
    P-Home, Q-Power, R-Defense, S-Telecom, T-Finance
  • (B)
    R-Home, S-Power, P-Defense, Q-Telecom, T-Finance
  • (C)
    P-Home, Q-Power, T-Defense, S-Telecom, U-Finance
  • (D)
    Q-Home, U-Power, T-Defense, R-Telecom, P-Finance

Answer (official key): B

Worked solution: in your report after you take this paper.

Q9 · General Aptitude · Numerical · 2 marks

The exports and imports (in crores of Rs.) of a country from the year 2000 to 2007 are given in the following bar chart. In which year is the combined percentage increase in imports and exports the highest?

Exports and imports chart for Q8

(Answer in integer)

Answer (official key): 2006

Worked solution: in your report after you take this paper.

Q10 · General Aptitude · MCQ · 2 marks

Choose the most appropriate equation for the function drawn as a thick line, in the plot below.

Graph for Q9

  • (A)
    x=y−∣y∣x = y - |y|
  • (B)
    x=−(y−∣y∣)x = -(y - |y|)
  • (C)
    x=y+∣y∣x = y + |y|
  • (D)
    x=−(y+∣y∣)x = -(y + |y|)

Answer (official key): B

Worked solution: in your report after you take this paper.

Q11 · Discrete Mathematics · MCQ · 1 mark

In a room there are only two types of people, namely Type 1 and Type 2. Type 1 people always tell the truth and Type 2 people always lie. You give a fair coin to a person in that room, without knowing which type he is from and tell him to toss it and hide the result from you till you ask for it.

Upon asking, the person replies the following:

“The result of the toss is head if and only if I am telling the truth.”

Which of the following options is correct?

  • (A)
    The result is head
  • (B)
    The result is tail
  • (C)
    If the person is of Type 2, then the result is tail
  • (D)
    If the person is of Type 1, then the result is tail

Answer (official key): A

Worked solution: in your report after you take this paper.

Q12 · Programming and Data Structures · Numerical · 1 mark

Consider a software project with the following information domain characteristics for calculation of function point metric.

  • Number of external inputs (I)=30(I) = 30
  • Number of external outputs (O)=60(O) = 60
  • Number of external enquiries (E)=23(E) = 23
  • Number of files (F)=08(F) = 08
  • Number of external interfaces (N)=02(N) = 02

It is given that the complexity weighting factors for I,O,E,FI, O, E, F and NN are 4, 5, 4, 10 and 7, respectively. It is also given that, out of fourteen value adjustment factors that influence the development effort, four factors are not applicable, each of the other factors have value 3, and each of the remaining factors have value 4. The computed value of function point metric is __________.

Answer (official key): 612 to 613

Worked solution: in your report after you take this paper.

Q13 · Digital Logic · MCQ · 1 mark

Let # be a binary operator defined as

X#Y=X′+Y′X \# Y = X' + Y'

where XX and YY are Boolean variables.

Consider the following two statements:

(S1)(P#Q)#R=P#(Q#R)(S1)\quad (P \# Q) \# R = P \# (Q \# R) (S2)Q#R=R#Q(S2)\quad Q \# R = R \# Q

Which of the following is/are true for the Boolean variables P,QP,Q and RR?

  • (A)
    Only S1 is true
  • (B)
    Only S2 is true
  • (C)
    Both S1 and S2 are true
  • (D)
    Neither S1 nor S2 are true

Answer (official key): B

Worked solution: in your report after you take this paper.

Q14 · Discrete Mathematics · Numerical · 1 mark

The number of 4 digit numbers having their digits in non-decreasing order from left to right, constructed using the digits belonging to the set {1,2,3}\{1,2,3\}, is __________.

Answer (official key): 15

Worked solution: in your report after you take this paper.

Q15 · Calculus · MCQ · 1 mark

The value of

lim⁡x→∞(1+x2)e−x\lim_{x\to\infty} (1+x^2)e^{-x}

is

  • (A)
    0
  • (B)
    12\frac{1}{2}
  • (C)
    1
  • (D)
    ∞\infty

Answer (official key): A

Worked solution: in your report after you take this paper.

Q16 · Theory of Computation · MCQ · 1 mark

Let LL be the language represented by the regular expression

Σ∗0011Σ∗\Sigma^*0011\Sigma^*

where Σ={0,1}\Sigma = \{0,1\}. What is the minimum number of states in a DFA that recognizes L‾\overline{L}, the complement of LL?

  • (A)
    4
  • (B)
    5
  • (C)
    6
  • (D)
    8

Answer (official key): B

Worked solution: in your report after you take this paper.

Q17 · Computer Organization and Architecture · MCQ · 1 mark

Consider a machine with a byte addressable main memory of 2202^{20} bytes, block size of 16 bytes and a direct mapped cache having 2122^{12} cache lines. Let the addresses of two consecutive bytes in main memory be (E201F)16(E201F)_{16} and (E2020)16(E2020)_{16}. What are the tag and cache line address in hex for main memory address (E201F)16(E201F)_{16}?

  • (A)
    E, 201
  • (B)
    F, 201
  • (C)
    E, E20
  • (D)
    2, 01F

Answer (official key): A

Worked solution: in your report after you take this paper.

Q18 · Computer Networks · MCQ · 1 mark

Consider a CSMA/CD network that transmits data at a rate of 100 Mbps (108(10^8 bits per second) over a 1 km cable with no repeaters. If the minimum frame size required for this network is 1250 bytes, what is the signal speed in km/sec in the cable?

  • (A)
    8000
  • (B)
    10000
  • (C)
    16000
  • (D)
    20000

Answer (official key): D

Worked solution: in your report after you take this paper.

Q19 · Programming and Data Structures · Numerical · 1 mark

Consider a software program that is artificially seeded with 100 faults. While testing this program, 159 faults are detected, out of which 75 faults are from those artificially seeded faults. Assuming that both real and seeded faults are of same nature and have same distribution, the estimated number of undetected real faults is __________.

Answer (official key): 28

Worked solution: in your report after you take this paper.

Q20 · Programming and Data Structures · Numerical · 1 mark

Consider a binary tree TT that has 200 leaf nodes. Then, the number of nodes in TT that have exactly two children are __________.

Answer (official key): 199

Worked solution: in your report after you take this paper.

Q21 · Programming and Data Structures · MCQ · 1 mark

Consider the following C program segment.

#include <stdio.h>

int main()
{
    char s1[7] = "1234", *p;
    p = s1 + 2;
    *p = '\0';
    printf("%s", s1);
}

What will be printed by the program?

  • (A)
    12
  • (B)
    120400
  • (C)
    1204
  • (D)
    1034

Answer (official key): A

Worked solution: in your report after you take this paper.

Q22 · Programming and Data Structures · MCQ · 1 mark

The result evaluating the postfix expression

10 5 + 60 6 / * 8 -

is

  • (A)
    284
  • (B)
    213
  • (C)
    142
  • (D)
    71

Answer (official key): C

Worked solution: in your report after you take this paper.

Q23 · Linear Algebra · MCQ · 1 mark

In the given matrix

[1−12010121]\begin{bmatrix} 1 & -1 & 2 \\ 0 & 1 & 0 \\ 1 & 2 & 1 \end{bmatrix}

one of the eigenvalues is 1. The eigenvectors corresponding to the eigenvalue 1 are

  • (A)
    {α(4,2,1)∣α≠0, α∈R}\{\alpha(4,2,1)\mid \alpha \ne 0,\ \alpha \in \mathbb{R}\}
  • (B)
    {α(−4,2,1)∣α≠0, α∈R}\{\alpha(-4,2,1)\mid \alpha \ne 0,\ \alpha \in \mathbb{R}\}
  • (C)
    {α(2,0,1)∣α≠0, α∈R}\{\alpha(\sqrt{2},0,1)\mid \alpha \ne 0,\ \alpha \in \mathbb{R}\}
  • (D)
    {α(−2,0,1)∣α≠0, α∈R}\{\alpha(-\sqrt{2},0,1)\mid \alpha \ne 0,\ \alpha \in \mathbb{R}\}

Answer (official key): B

Worked solution: in your report after you take this paper.

Q24 · Programming and Data Structures · MCQ · 1 mark

While inserting the elements 71, 65, 84, 69, 67, 83 in an empty binary search tree (BST) in the sequence shown, the element in the lowest level is

  • (A)
    65
  • (B)
    67
  • (C)
    69
  • (D)
    83

Answer (official key): B

Worked solution: in your report after you take this paper.

Q25 · Computer Networks · MCQ · 1 mark

In a web server, ten webpages are stored with the URLs of the form http://www.yourname.com/var.html, where var is a different number from 1 to 10 for each webpage. Suppose the client stores the webpage with var = 1 locally, edits and then tests. Rest of the webpages remains on the web server. W1 contains several relative URLs of the form ...var.html referring to the other webpages.

Which one of the following statements needs to be added in W1, so that all the relative URLs in W1 refer to the appropriate webpages on the web server?

  • (A)
    <a href: “http://www.yourname.com/”, href: “...var.html”>
  • (B)
    <base href: “http://www.yourname.com/”>
  • (C)
    <a href: “http://www.yourname.com/”>
  • (D)
    <base href: “http://www.yourname.com”, range:“...var.html”>

Answer (official key): B

Worked solution: in your report after you take this paper.

Q26 · Databases · MCQ · 1 mark

Consider the following relation:

Cinema(theater, address, capacity)Cinema(theater,\ address,\ capacity)

Which of the following options will be needed at the end of the SQL query

SELECT P1.address
FROM Cinema P1

such that it always finds the addresses of theaters with maximum capacity?

  • (A)
    WHERE P1.capacity >= ALL (select P2.capacity from Cinema P2)
  • (B)
    WHERE P1.capacity >= ANY (select P2.capacity from Cinema P2)
  • (C)
    WHERE P1.capacity > ALL (select max(P2.capacity) from Cinema P2)
  • (D)
    WHERE P1.capacity > ANY (select max(P2.capacity) from Cinema P2)

Answer (official key): A

Worked solution: in your report after you take this paper.

Q27 · Algorithms · MCQ · 1 mark

Consider the equality

∑i=0ni3=X\sum_{i=0}^{n} i^3 = X

and the following choices for XX:

I. Θ(n4)\Theta(n^4)
II. Θ(n5)\Theta(n^5)
III. O(n5)O(n^5)
IV. Ω(n3)\Omega(n^3)

The equality above remains correct if XX is replaced by

  • (A)
    Only I
  • (B)
    Only II
  • (C)
    I or III or IV but not II
  • (D)
    II or III or IV but not I

Answer (official key): C

Worked solution: in your report after you take this paper.

Q28 · Compiler Design · MCQ · 1 mark

Among simple LR (SLR), canonical LR, and look-ahead LR (LALR), which of the following pairs identify the method that is very easy to implement and the method that is the most powerful, in that order?

  • (A)
    SLR, LALR
  • (B)
    Canonical LR, LALR
  • (C)
    SLR, canonical LR
  • (D)
    LALR, canonical LR

Answer (official key): C

Worked solution: in your report after you take this paper.

Q29 · Operating System · MCQ · 1 mark

The maximum number of processes that can be in Ready state for a computer system with nn CPUs is

  • (A)
    nn
  • (B)
    n2n^2
  • (C)
    2n2^n
  • (D)
    Independent of nn

Answer (official key): D

Worked solution: in your report after you take this paper.

Q30 · Operating System · MCQ · 1 mark

Two processes XX and YY need to access a critical section. Consider the following synchronization construct used by both the processes.

/* Process X */
while (true) {
    varP = true;
    while (varQ == true) {
        /* Critical Section */
        varP = false;
    }
}

/* Process Y */
while (true) {
    varQ = true;
    while (varP == true) {
        /* Critical Section */
        varQ = false;
    }
}

Here, varP and varQ are shared variables and both are initialized to false. Which one of the following statements is true?

  • (A)
    The proposed solution prevents deadlock but fails to guarantee mutual exclusion
  • (B)
    The proposed solution guarantees mutual exclusion but fails to prevent deadlock
  • (C)
    The proposed solution guarantees mutual exclusion and prevents deadlock
  • (D)
    The proposed solution fails to prevent deadlock and fails to guarantee mutual exclusion

Answer (official key): A

Worked solution: in your report after you take this paper.

Q31 · Programming and Data Structures · MCQ · 1 mark

Consider the following array of elements:

⟨89,19,50,17,12,15,2,5,7,11,6,9,100⟩\langle 89, 19, 50, 17, 12, 15, 2, 5, 7, 11, 6, 9, 100 \rangle

The minimum number of interchanges needed to convert it into a max-heap is

  • (A)
    4
  • (B)
    5
  • (C)
    2
  • (D)
    3

Answer (official key): D

Worked solution: in your report after you take this paper.

Q32 · Programming and Data Structures · Numerical · 1 mark

Given a hash table TT with 25 slots that stores 2000 elements, the load factor α\alpha for TT is __________.

Answer (official key): 80

Worked solution: in your report after you take this paper.

Q33 · Databases · MCQ · 1 mark

Consider the relation X(P,Q,R,S,T,U)X(P,Q,R,S,T,U) with the following set of functional dependencies:

F={{P,R}→{S,T},{P,S,U}→{Q,R}}F = \{ \{P,R\}\to\{S,T\}, \{P,S,U\}\to\{Q,R\} \}

Which of the following is the trivial functional dependency in F+F^+, where F+F^+ is the closure of FF?

  • (A)
    {P,R}→{S,T}\{P,R\}\to\{S,T\}
  • (B)
    {P,R}→{R,T}\{P,R\}\to\{R,T\}
  • (C)
    {P,S}→{S}\{P,S\}\to\{S\}
  • (D)
    {P,S,U}→{Q}\{P,S,U\}\to\{Q\}

Answer (official key): C

Worked solution: in your report after you take this paper.

Q34 · Computer Networks · MCQ · 1 mark

Consider the following statements.

I. TCP connections are full duplex.
II. TCP has no option for selective acknowledgement.
III. TCP connections are message streams.

Which of the following is correct?

  • (A)
    Only I is correct
  • (B)
    Only I and III are correct
  • (C)
    Only II and III are correct
  • (D)
    All of I, II and III are correct

Answer (official key): A

Worked solution: in your report after you take this paper.

Q35 · Discrete Mathematics · MCQ · 1 mark

Suppose UU is the power set of the set S={1,2,3,4,5,6}S = \{1,2,3,4,5,6\}. For any T∈UT \in U, let ∣T∣|T| denote the number of elements in TT and T′T' denote the complement of TT. For any T,R∈UT, R \in U, let T∖RT \setminus R be the set of all elements in TT which are not in RR.

Which one of the following is true?

  • (A)
    ∀X∈U (∣X∣=∣X′∣)\forall X \in U\ (|X| = |X'|)
  • (B)
    ∃X∈U ∃Y∈U (∣X∣=5, ∣Y∣=5 and X∩Y=∅)\exists X \in U\ \exists Y \in U\ (|X|=5,\ |Y|=5\ \text{and}\ X \cap Y=\varnothing)
  • (C)
    ∀X∈U ∀Y∈U (∣X∣=2, ∣Y∣=3 and X∖Y=∅)\forall X \in U\ \forall Y \in U\ (|X|=2,\ |Y|=3\ \text{and}\ X \setminus Y=\varnothing)
  • (D)
    ∀X∈U ∀Y∈U (X∖Y=Y′∖X′)\forall X \in U\ \forall Y \in U\ (X \setminus Y = Y' \setminus X')

Answer (official key): D

Worked solution: in your report after you take this paper.

Q36 · Operating System · MCQ · 2 marks

Consider the following policies for preventing deadlock in a system with mutually exclusive resources.

I. Processes should acquire all their resources at the beginning of execution. If any resource is not available, all resources acquired so far are released.
II. The resources are numbered uniquely, and processes are allowed to request resources only in increasing resource numbers.
III. The resources are numbered uniquely, and processes are allowed to request resources only in decreasing resource numbers.
IV. The resources are numbered uniquely. A process is allowed to request only for a resource with resource number larger than its currently held resources.

Which of the above policies can be used for preventing deadlock?

  • (A)
    Any one of I and III but not II or IV
  • (B)
    Any one of I, III and IV but not II
  • (C)
    Any one of II and III but not I or IV
  • (D)
    Any one of I, II, III and IV

Answer (official key): D

Read the worked solution

Q37 · Probability and Statistics · Numerical · 2 marks

Suppose XiX_i for i=1,2,3i=1,2,3 are independent and identically distributed random variables whose probability mass functions are

Pr[Xi=0]=Pr[Xi=1]=12Pr[X_i=0] = Pr[X_i=1] = \frac{1}{2}

for i=1,2,3i=1,2,3. Define another random variable

Y=X1X2⊕X3,Y = X_1X_2 \oplus X_3,

where ⊕\oplus denotes XOR. Then

Pr[Y=0∣X3=0]=Pr[Y=0 \mid X_3=0] =

__________.

Answer (official key): 0.75

Read the worked solution

Q38 · Compiler Design · MCQ · 2 marks

Consider the following grammar GG:

S→F∣HS \to F \mid H F→p∣cF \to p \mid c H→d∣cH \to d \mid c

where S,F,HS,F,H are non-terminal symbols, and p,d,cp,d,c are terminal symbols. Which of the following statement(s) is/are correct?

S1. LL(1) can parse all strings that are generated using grammar GG.
S2. LR(1) can parse all strings that are generated using grammar GG.

  • (A)
    Only S1
  • (B)
    Only S2
  • (C)
    Both S1 and S2
  • (D)
    Neither S1 nor S2

Answer (official key): D

Read the worked solution

Q39 · Databases · Numerical · 2 marks

Consider a B+ tree in which the search key is 12 bytes long, block size is 1024 bytes, record pointer is 10 bytes long and block pointer is 8 bytes long. The maximum number of keys that can be accommodated in each non-leaf node of the tree is __________.

Answer (official key): 50

Worked solution: in your report after you take this paper.

Q40 · Computer Organization and Architecture · Numerical · 2 marks

Consider the following reservation table for a pipeline having three stages S1S_1, S2S_2 and S3S_3.

StageTime 1Time 2Time 3Time 4Time 5
S1S_1XX
S2S_2XX
S3S_3X

The minimum average latency (MAL) is __________.

Answer (official key): 3

Worked solution: in your report after you take this paper.

Q41 · Algorithms · MCQ · 2 marks

Assume that a mergesort algorithm in the worst case takes 30 seconds for an input of size 64. Which of the following most closely approximates the maximum input size of a problem that can be solved in 6 minutes?

  • (A)
    256
  • (B)
    512
  • (C)
    1024
  • (D)
    2048

Answer (official key): B

Worked solution: in your report after you take this paper.

Q42 · Databases · MCQ · 2 marks

Consider the following partial schedule SS involving two transactions T1T1 and T2T2. Only the read and write operations are shown. The read operation on data item PP is denoted by read(P) and the write operation on data item PP is denoted by write(P).

TimeT1T2
1read(A)
2write(A)
3read(C)
4write(C)
5read(B)
6write(B)
7read(A)
8commit
9read(B)

Suppose that transaction T1T1 fails immediately after time instance 9. Which one of the following statements is correct?

  • (A)
    T2 must be aborted and then both T1 and T2 must be re-started to ensure transaction atomicity
  • (B)
    Schedule S is non-recoverable and cannot ensure transaction atomicity
  • (C)
    Only T2 must be aborted and then re-started to ensure transaction atomicity
  • (D)
    Schedule S is recoverable and can ensure atomicity and nothing else needs to be done

Answer (official key): B

Worked solution: in your report after you take this paper.

Q43 · Theory of Computation · MCQ · 2 marks

Language L1L_1 is polynomial-time reducible to language L2L_2. Language L3L_3 is polynomial-time reducible to L2L_2, which in turn is polynomial-time reducible to language L4L_4. Which of the following is/are true?

I. If L4∈PL_4 \in P, then L2∈PL_2 \in P
II. If L1∈PL_1 \in P or L3∈PL_3 \in P, then L2∈PL_2 \in P
III. L1∈PL_1 \in P if and only if L3∈PL_3 \in P
IV. If L4∈PL_4 \in P, then L1∈PL_1 \in P and L3∈PL_3 \in P

  • (A)
    II only
  • (B)
    III only
  • (C)
    I and IV only
  • (D)
    I only

Answer (official key): C

Worked solution: in your report after you take this paper.

Q44 · Computer Organization and Architecture · MCQ · 2 marks

Consider the following code sequence having five instructions I1I_1 to I5I_5. Each instruction has the following format:

OP Ri, Rj, Rk

where operation OP is performed on contents of registers Rj and Rk, and the result is stored in register Ri.

I1: ADD R1, R2, R3
I2: MUL R7, R1, R3
I3: SUB R4, R1, R5
I4: ADD R3, R2, R4
I5: MUL R7, R8, R9

Consider the following statements:

S1: There is an anti-dependence between instructions I2I_2 and I5I_5.
S2: There is an anti-dependence between instructions I2I_2 and I4I_4.
S3: Within an instruction pipeline, an anti-dependence always creates one or more stalls.

Which one of the above statements is/are correct?

  • (A)
    Only S1 is true
  • (B)
    Only S2 is true
  • (C)
    Only S1 and S3 are true
  • (D)
    Only S2 and S3 are true

Answer (official key): B

Worked solution: in your report after you take this paper.

Q45 · Discrete Mathematics · Numerical · 2 marks

Consider the equation

(43)x=(y3)8(43)_x = (y3)_8

where xx and yy are unknown. The number of possible solutions is __________.

Answer (official key): 5

Worked solution: in your report after you take this paper.

Q46 · Theory of Computation · MCQ · 2 marks

Which of the following languages are context-free?

L1={ambnanbm∣m,n≥1}L_1 = \{a^m b^n a^n b^m \mid m,n \ge 1\} L2={ambnambn∣m,n≥1}L_2 = \{a^m b^n a^m b^n \mid m,n \ge 1\} L3={ambn∣m=2n+1}L_3 = \{a^m b^n \mid m = 2n+1\}
  • (A)
    L1L_1 and L2L_2 only
  • (B)
    L1L_1 and L3L_3 only
  • (C)
    L2L_2 and L3L_3 only
  • (D)
    L3L_3 only

Answer (official key): B

Worked solution: in your report after you take this paper.

Q47 · Computer Networks · Numerical · 2 marks

In the network 200.10.11.144/27, the fourth octet in decimal of the last IP address of the network which can be assigned to a host is __________.

Answer (official key): 158

Worked solution: in your report after you take this paper.

Q48 · Calculus · MCQ · 2 marks

If for non-zero xx,

af(x)+bf(1x)=1x−25,a f(x) + b f\left(\frac{1}{x}\right) = \frac{1}{x} - 25,

where a≠ba \ne b, then

∫12f(x) dx\int_1^2 f(x)\,dx

is

  • (A)
    1a2−b2[a(ln⁡2−25)+47b2]\frac{1}{a^2-b^2}\left[a(\ln 2 - 25)+\frac{47b}{2}\right]
  • (B)
    1a2−b2[a(2ln⁡2−25)−47b2]\frac{1}{a^2-b^2}\left[a(2\ln 2 - 25)-\frac{47b}{2}\right]
  • (C)
    1a2−b2[a(2ln⁡2−25)+47b2]\frac{1}{a^2-b^2}\left[a(2\ln 2 - 25)+\frac{47b}{2}\right]
  • (D)
    1a2−b2[a(ln⁡2−25)−47b2]\frac{1}{a^2-b^2}\left[a(\ln 2 - 25)-\frac{47b}{2}\right]

Answer (official key): A

Worked solution: in your report after you take this paper.

Q49 · Algorithms · Numerical · 2 marks

Suppose c=⟨c[0],…,c[k−1]⟩c = \langle c[0],\ldots,c[k-1]\rangle is an array of length kk, where all entries are from the set {0,1}\{0,1\}. For any positive integers aa and nn, consider the following pseudocode.

DOSOMETHING(c,a,n)
z <- 1
for i <- 0 to k-1
    do z <- z^2 mod n
       if c[i] = 1
          then z <- (z * a) mod n
return z

If k=4k=4, c=⟨1,0,1,1⟩c=\langle 1,0,1,1\rangle, a=2a=2 and n=8n=8, then the output of DOSOMETHING(c,a,n) is __________.

Answer (official key): 0

Worked solution: in your report after you take this paper.

Q50 · Computer Networks · Numerical · 2 marks

Two hosts are connected via a packet switch with 10710^7 bits per second links. Each link has a propagation delay of 20 microseconds. The switch begins forwarding a packet 35 microseconds after it receives the same. If 10000 bits of data are to be transmitted between the two hosts using a packet size of 5000 bits, the time elapsed between the transmission of the first bit of data and the reception of the last bit of the data in microseconds is __________.

Answer (official key): 1575

Worked solution: in your report after you take this paper.

Q51 · Linear Algebra · MCQ · 2 marks

If the following system has non-trivial solution,

px+qy+rz=0px + qy + rz = 0 qx+ry+pz=0qx + ry + pz = 0 rx+py+qz=0rx + py + qz = 0

then which one of the following options is TRUE?

  • (A)
    p−q+r=0p-q+r=0 or p=q=−rp=q=-r
  • (B)
    p+q−r=0p+q-r=0 or p=−q=rp=-q=r
  • (C)
    p+q+r=0p+q+r=0 or p=q=rp=q=r
  • (D)
    p−q+r=0p-q+r=0 or p=−q=−rp=-q=-r

Answer (official key): C

Worked solution: in your report after you take this paper.

Q52 · Algorithms · Numerical · 2 marks

Let GG be a connected undirected graph of 100 vertices and 300 edges. The weight of a minimum spanning tree of GG is 500. When the weight of each edge of GG is increased by five, the weight of a minimum spanning tree becomes __________.

Answer (official key): 995

Worked solution: in your report after you take this paper.

Q53 · Digital Logic · Numerical · 2 marks

The total number of prime implicants of the function

f(w,x,y,z)=Σ(0,2,4,5,6,10)f(w,x,y,z)=\Sigma(0,2,4,5,6,10)

is __________.

Answer (official key): 3

Worked solution: in your report after you take this paper.

Q54 · Digital Logic · MCQ · 2 marks

Given the function

F=P′+QR,F = P' + QR,

where FF is a function in three Boolean variables P,Q,RP,Q,R and P′=¬PP' = \neg P, consider the following statements:

(S1)F=Σ(4,5,6)(S1)\quad F = \Sigma(4,5,6) (S2)F=Σ(0,1,2,3,7)(S2)\quad F = \Sigma(0,1,2,3,7) (S3)F=Π(4,5,6)(S3)\quad F = \Pi(4,5,6) (S4)F=Π(0,1,2,3,7)(S4)\quad F = \Pi(0,1,2,3,7)

Which of the following is true?

  • (A)
    S1 False, S2 True, S3 True, S4 False
  • (B)
    S1 True, S2 False, S3 False, S4 True
  • (C)
    S1 False, S2 False, S3 True, S4 True
  • (D)
    S1 True, S2 True, S3 False, S4 False

Answer (official key): A

Worked solution: in your report after you take this paper.

Q55 · Programming and Data Structures · Numerical · 2 marks

Consider the following C program.

#include <stdio.h>
int main()
{
    int i, j, k = 0;
    j = 2 * 3 / 4 + 2.0 / 5 + 8 / 5;
    k -= --j;
    for (i = 0; i < 5; i++)
    {
        switch(i + k)
        {
            case 1:
            case 2: printf("\n%d", i+k);
            case 3: printf("\n%d", i+k);
            default: printf("\n%d", i+k);
        }
    }
    return 0;
}

The number of times printf statement is executed is __________.

Answer (official key): 10

Worked solution: in your report after you take this paper.

Q56 · Algorithms · MCQ · 2 marks

Let f(n)=nf(n)=n and g(n)=n(1+sin⁡n)g(n)=n^{(1+\sin n)}, where nn is a positive integer. Which of the following statements is/are correct?

I. f(n)=O(g(n))f(n)=O(g(n))
II. f(n)=Ω(g(n))f(n)=\Omega(g(n))

  • (A)
    Only I
  • (B)
    Only II
  • (C)
    Both I and II
  • (D)
    Neither I nor II

Answer (official key): D

Worked solution: in your report after you take this paper.

Q57 · Operating System · MCQ · 2 marks

For the processes listed in the following table, which of the following scheduling schemes will give the lowest average turnaround time?

ProcessArrival TimeProcessing Time
A03
B16
C44
D62
  • (A)
    First Come First Serve
  • (B)
    Non-preemptive Shortest Job First
  • (C)
    Shortest Remaining Time
  • (D)
    Round Robin with Quantum value two

Answer (official key): C

Worked solution: in your report after you take this paper.

Q58 · Programming and Data Structures · Numerical · 2 marks

Consider the following C program.

#include <stdio.h>
int main()
{
    static int a[] = {10, 20, 30, 40, 50};
    static int *p[] = {a, a+3, a+4, a+1, a+2};
    int **ptr = p;
    ptr++;
    printf("%d%d", ptr-p, **ptr);
}

The output of the program is __________.

Answer (official key): 140

Worked solution: in your report after you take this paper.

Q59 · Computer Networks · Numerical · 2 marks

Consider a network connecting two systems located 8000 kilometers apart. The bandwidth of the network is 500×106500 \times 10^6 bits per second. The propagation speed of the media is 4×1064 \times 10^6 meters per second. It is needed to design a Go-Back-N sliding window protocol for this network. The average packet size is 10710^7 bits. The network is to be used to its full capacity. Assume that processing delays at nodes are negligible.

Then, the minimum size in bits of the sequence number field has to be __________.

Answer (official key): 8

Worked solution: in your report after you take this paper.

Q60 · Programming and Data Structures · MCQ · 2 marks

Consider the following recursive C function.

void get(int n)
{
    if (n < 1) return;
    get(n-1);
    get(n-3);
    printf("%d", n);
}

If get(6) is called in main(), then how many times will the get() function be invoked before returning to main()?

  • (A)
    15
  • (B)
    25
  • (C)
    35
  • (D)
    45

Answer (official key): B

Worked solution: in your report after you take this paper.

Q61 · Programming and Data Structures · Numerical · 2 marks

Consider the following C program.

#include <stdio.h>
int f1(void);
int f2(void);
int f3(void);
int x = 10;

int main()
{
    int x = 1;
    x += f1() + f2() + f3() + f2();
    printf("%d", x);
    return 0;
}

int f1() { int x = 25; x++; return x; }
int f2() { static int x = 50; x++; return x; }
int f3() { x *= 10; return x; }

The output of the program is __________.

Answer (official key): 230

Worked solution: in your report after you take this paper.

Q62 · Computer Organization and Architecture · MCQ · 2 marks

Consider the following two C code segments. Y and X are one and two dimensional arrays of size nn and n×nn \times n respectively, where 2≤n≤102 \le n \le 10. Assume that in both code segments, elements of Y are initialized to 0 and each element X[i][j] of array X is initialized to i+j. Further assume that when stored in main memory, all elements of X are in the same main memory page frame.

Code segment 1:

for (i = 0; i < n; i++)
    Y[i] += X[0][i];

Code segment 2:

for (i = 0; i < n; i++)
    Y[i] += X[i][0];

Which of the following statements is/are correct?

S1: Final contents of array Y will be same in both code segments.
S2: Elements of array X accessed inside the loop shown in code segment 1 are contiguous in main memory.
S3: Elements of array X accessed inside the loop shown in code segment 2 are contiguous in main memory.

  • (A)
    Only S2 is correct
  • (B)
    Only S3 is correct
  • (C)
    Only S1 and S2 are correct
  • (D)
    Only S1 and S3 are correct

Answer (official key): C

Worked solution: in your report after you take this paper.

Q63 · Discrete Mathematics · MCQ · 2 marks

Let RR be a relation on the set of ordered pairs of positive integers such that ((p,q),(r,s))∈R((p,q),(r,s)) \in R if and only if p−s=q−rp-s=q-r. Which one of the following is true about RR?

  • (A)
    Both reflexive and symmetric
  • (B)
    Reflexive but not symmetric
  • (C)
    Not reflexive but symmetric
  • (D)
    Neither reflexive nor symmetric

Answer (official key): C

Worked solution: in your report after you take this paper.

Q64 · Calculus · Numerical · 2 marks

The velocity vv in kilometer/minute of a motorbike which starts from rest is given at fixed intervals of time tt in minutes as follows:

tt2468101214161820
vv10182529322011520

The approximate distance in kilometers rounded to two places of decimal covered in 20 minutes using Simpson’s 1/31/3 rule is __________.

Answer (official key): 308 to 310

Worked solution: in your report after you take this paper.

Q65 · Programming and Data Structures · MCQ · 2 marks

Consider three software items: Program-X, Control Flow Diagram of Program-Y and Control Flow Diagram of Program-Z as shown below.

Programs and control-flow diagrams for Q58

The values of McCabe’s cyclomatic complexity of Program-X, Program-Y, and Program-Z respectively are:

  • (A)
    4, 4, 7
  • (B)
    3, 4, 7
  • (C)
    4, 4, 8
  • (D)
    4, 3, 8

Answer (official key): A

Worked solution: in your report after you take this paper.