Sail E0 Webinar

MCQs

Total Questions : 65 | Page 6 of 7 pages
Question 51.

Match the problem domains in Group I with the solution technologies in Group II.  

                                        Group I                                                    Group II 

(p) Services oriented computing                                            (1) Interoperability 

(q) Heterogeneous communicating systems                          (2) BPMN 

(R) Information representation                                              (3) Publish-find bind 

(S) Process description                                                          (4) XML


  1.    P - 1, Q - 2, R - 3, S - 4
  2.    P - 3, Q - 4, R - 2, S - 1
  3.    P - 3, Q - 1, R - 4, S - 2
  4.    P - 4, Q - 3, R - 2, S - 1
 Discuss Question
Answer: Option C. -> P - 3, Q - 1, R - 4, S - 2



Question 52.

The transport layer protocols used for real time multimedia, file transfer, DNS and
email, respectively are


  1.    TCP, UDP, UDP and TCP
  2.    UDP, TCP, TCP and UDP
  3.    UDP, TCP, UDP and TCP
  4.    TCP, UDP, TCP and UDP
 Discuss Question
Answer: Option C. -> UDP, TCP, UDP and TCP

Real time multimedia needs connectionless service, so under lying transport layer protocol
used is UDP  

File transfer rums over TCP protocol with port no - 21 

 DNS runs over UDP protocol within port no - 53 

 Email needs SMTP protocol which runs over TCP protocol within port no - 25  


Question 53.

Assume that source S and destination D are connected through two intermediate routers 

labeled R. Determine how many times each packet has to visit the network layer and the 

data
link layer during a transmission from S to D. 

                       S                       R                 R                        D 


  1.    Network layer - 4 times and Data link layer-4 times
  2.    Network layer - 4 times and Data link layer-3 times
  3.    Network layer - 4 times and Data link layer-6 times
  4.    Network layer - 2 times and Data link layer-6 times
 Discuss Question
Answer: Option C. -> Network layer - 4 times and Data link layer-6 times

Application      

Transport                                                                         Application

Network                                                                           Transport

Datalink              Network                    Network                Network 

Physical              Datalink                     Datalink                Datalink

source                 Physical                    Physical                 Physical

  (5)                         R                               R                     Destination

                                                                                              (D)

From above given diagram, its early visible that packet will visit network layer 4 times, once 

at each node [S, R, R, D] and packet will visit Data Link layer 6 times. One time at S and one

 time at D, then two times for each intermediate router R as data link layer is used for link to

link communication.

Once at packet reaches R and goes up from physical - DL- Network and second time when

packet coming out of router in order Network - DL- Physical  



Question 54.

Using public key cryptography, X adds a digital signature `sigma`  to message M, encrypts < M, `sigma`  >, and sends it to Y, where is it  decrypted. Which one of the following sequences of keys is
used for the operations?  


  1.    Encryption: X's private key followed by Y's private key; Decryption: X's public key followed by Y's public key
  2.    Encryption: X's private key followed by Y's public key; Decryption: X's public key followed by Y's private key
  3.    Encryption: X's public key followed by Y's private key; Decryption: Y's public key followed by X's private key
  4.    Encryption: X's private key followed by Y's public key; Decryption: Y's private key followed by X's public key
 Discuss Question
Answer: Option D. -> Encryption: X's private key followed by Y's public key; Decryption: Y's private key followed by X's public key

         X                                               Y

   X - public                                   Y - public

   X - private                                  Y - private


                      Source has to encrypt with its private key for

                     forming   Digital  signature  for  Authentication

Encryption    {source has to encrypt the (M,`sigma`) with Y ' s

                     public key to send it confidentially 


                      Destination Y has to decrypt first

Decryption     with its private key, then decrypt 

                      usin g source public key



Question 55.

An index is clustered, if 


  1.    it is on a set of fields that form a candidate key
  2.    it is on a set of fields that include the primary key
  3.    the data records of the file are organized in the same order as the data entries of the index
  4.    the data records of the file are organized not in the same order as the data entries of the index
 Discuss Question
Answer: Option C. -> the data records of the file are organized in the same order as the data entries of the index

Clustered index is built on ordering non key field and hence if the index is clustered then the 

data records of the file are organized in the same order as the data entries of the index.


Question 56.

Three concurrent processes X, Y, and Z execute three different code segments that access and 

update certain shared variables. Process X executes the P operation (i.e., wait) on semaphores 

a, b and c; process Y executes the P operation on semaphores b, c and d; process Z executes 

the P operation on semaphores c, d, and a before entering the respective code segments. After 

completing the execution of its code segment, each process invokes the V operation (i.e.,
signal) 

on its three semaphores. All semaphores are binary semaphores initialized to one.
Which one of 

the following represents a deadlock-free order of invoking the P operations by
the processes?  


  1.    X : P(a)P(b)P(c) Y : P(b)P(c)P(d) Z : P(c)P(d)P(a)
  2.    X : P(b)P(a)P(c) Y : P(b)P(c)P(d) Z : P(a)P(c)P(d)
  3.    X : P(b)P(a)P(c) Y : P(c)P(b)P(d) Z : P(a)P(c)P(d)
  4.    X : P(a)P(b)P(c) Y : P(c)P(b)P(d) Z : P(c)P(d)P(a)
 Discuss Question
Answer: Option B. -> X : P(b)P(a)P(c) Y : P(b)P(c)P(d) Z : P(a)P(c)P(d)

Suppose X performs P(b) and preempts, Y gets chance, but cannot do its first wait i.e., P(b), 

so waits for X, now Z gets the chance and performs P(a) and preempts, next X gets chance. 

X cannot continue as wait on 'a' is done by Z already, so X waits for Z. At this time Z cancontinue

 its operations as down on c and d. Once Z finishes, X can do its operations and so Y.
In any of 

execution order of X, Y, Z one process can continue and finish, such that waiting is
not circular. 

In options (A),(C) and (D) we can easily find circular wait, thus deadlock  


Question 57.

What is the time complexity of Bellman-Ford single-source shortest path algorithm on a
complete graph of n vertices?


  1.    `Theta` (`n^2`)
  2.    `Theta`(`n^2`log n)
  3.    `Theta`(`n^3`)
  4.    `Theta`(`n^3`log n)
 Discuss Question
Answer: Option C. -> `Theta`(`n^3`)

Bellman-ford time complexity:  `Theta`(lVlxlEl)

For complete graph: l E l = `(n(n - 1))/2`

                                           l V l = n

                                         `:.`  `Theta` (n x `(n( - 1))/2`) = `Theta` (`n^3`)



Question 58.

Which of the following statements is/are FALSE? 

 (1) For every non-deterministic Turing machine, there exists an equivalent deterministic
Turing machine. 

 (2) Turing recognizable languages are closed under union and complementation. 

 (3) Turing decidable languages are closed under intersection and complementation 

 (4) Turing recognizable languages are closed under union and intersection. 


  1.    1 and 4 only
  2.    1 and 3 only
  3.    2 only
  4.    3 only
 Discuss Question
Answer: Option C. -> 2 only

(1) NTM `cong`  DTM 

(2) RELs are closed under union & but not complementation 

(3) Turing decidable languages are recursive and recursive languages are closed under 

 intersection and complementation

(4) RELs are closed under union & intersection but not under complementation 



Question 59.

Which of the following statements are TRUE? 

(1) The problem of determining whether there exists a cycle in an undirected graph is in P. 

 (2) The problem of determining whether there exists a cycle in an undirected graph is in NP. 

 (3) If a problem A is NP-Complete, there exists a non-deterministic polynomial time
algorithm to solve A


  1.    1,2 and 3
  2.    1 and 2 only
  3.    2 and 3 only
  4.    1 and 3 only
 Discuss Question
Answer: Option A. -> 1,2 and 3

1. Cycle detection using DFS:  O(V + E) = O(`V^ 2`)  and it is polynomial problem 

2. Every P-problem is NP (since P `subset`  NP)

NP complete `in`  NP

Hence, NP-complete can be solved in non-deterministic polynomial time 



Question 60.

In a k-way set associative cache, the cache is divided into v sets, each of which consists of k
lines. 

The lines of a set are placed in sequence one after another. The lines in set s are
sequenced before 

the lines in set (s+1). The main memory blocks are numbered 0 onwards.
The main memory block 

numbered j must be mapped to any one of the cache lines from 


  1.    ( j mod v )* k to ( j mod v )*k + ( k - 1 )
  2.    ( j mod v ) to ( j mod v ) + ( k - 1 )
  3.    ( j mod k ) to ( j mod k ) + ( v - 1 )
  4.    ( j mod k )* v to ( j mod k )* v + ( v - 1 )
 Discuss Question
Answer: Option A. -> ( j mod v )* k to ( j mod v )*k + ( k - 1 )

Position of main memory block in the cache (set) = (main memory block number) MOD 

(number of sets in the cache). 

As the lines in the set are placed in sequence, we can have the lines from 0 to (K – 1) in each
set.  

Number of sets = v, main memory block number = j 

 First line of cache = (j mod v)*k; last line of cache = (j mod v)*k + (k – 1) 


Latest Videos

Latest Test Papers