Computer Science Study Materials for Competitive Exams

Sample Questions, Previous Year Solved Papers, Study Materials For Competitive Examinations Like UGC NET, SET And GATE Computer Science.

Saturday, 2 December 2017

71.       Consider a single perceptron with sign activation function. The perceptron is represented by weight vector [0.4 −0.3 0.1]t and a bias θ=0. If the input vector to the perceptron is X=[0.2 0.6 0.5] then the output of the perceptron is :
(1) 1
(2) 0
(3) −0.05
(4) −1
Answer: 3
72.       The Sigmoid activation function f(t) is defined as :
Answer: 4
73.       Consider the following statements :
(a) UNIX provides three types of permissions
* Read
* Write
* Execute
(b) UNIX provides three sets of permissions
* permission for owner
* permission for group
* permission for others
Which of the above statement/s is/are true?
(1) Only (a)
(2) Only (b)
(3) Both (a) and (b)
(4) Neither (a) nor (b)
Answer: 3
74.       Which of the following routing technique / techniques is / are used in distributed systems?
(a) Fixed Routing
(b) Virtual Routing
(c) Dynamic Routing
Code :
(1) (a) only
(2) (a) and (b) only
(3) (c) only
(4) All (a), (b), (c)
Answer: 4
75.       Match the following WINDOWS system calls and UNIX system calls with reference to process control and File manipulation.
Windows
(a) Create - process ()
(b) WaitForSingleObject ()
(c) CreateFile ()
(d) CloseHandle ()
UNIX
(i) Open ()
(ii) Close ()
(iii) Fork ()
(iv) Wait ()
Code :
      (a) (b) (c) (d)
(1) (iii) (iv) (i) (ii)
(2) (iv) (iii) (i) (ii)
(3) (iv) (iii) (ii) (i)
(4) (iii) (iv) (ii) (i)
Answer: 1
Advertisement

Friday, 1 December 2017

61.       Which of the following statements is not correct?
(1) Every recursive language is recursively enumerable.
(2) L = {0n 1n 0n | n=1, 2 , 3, ....} is recursively enumerable.
(3) Recursive languages are closed under intersection.
(4) Recursive languages are not closed under intersection.
Answer: 4
62.       Context free grammar is not closed under :
(1) Concatenation
(2) Complementation
(3) Kleene Star
(4) Union
Answer: 2
63.       Consider the following languages :
L1 = {am bn | m ≠ n}
L2 = {am bn | m = 2n+1}
L3 = {am bn | m ≠ 2n}
Which one of the following statement is correct?
(1) Only L1 and L2 are context free languages
(2) Only L1 and L3 are context free languages
(3) Only L2 and L3 are context free languages
(4) L1, L2 and L3 are context free languages
Answer: 4
64.       A 4×4 DFT matrix is given by :
(j2=−1)
Where values of x and y are ..........., ............. respectively.
(1) 1, −1
(2) −1, 1
(3) −j, j
(4) j, −j
Answer: 4
65.       Entropy of a discrete random variable with possible values {x1, x2, ..., xn} and probability density function P(X) is :
The value of b gives the units of entropy. The unit for b=10 is :
(1) bits
(2) bann
(3) nats
(4) deca
Answer: 3
66.       For any binary (n, h) linear code with minimum distance (2t+1) or greater
(1) 2t+1
(2) t+1
(3) t−1
(4) t
Answer: 4
67.       Which of the following is a valid reason for causing degeneracy in a transportation problem? Here m is no. of rows and n is no. of columns in transportation table.
(1) When the number of allocations is m+n−1.
(2) When two or more occupied cells become unoccupied simultaneously.
(3) When the number of allocations is less than m+n−1.
(4) When a loop cannot be drawn without using unoccupied cells, except the starting cell of the loop.
Answer: 3
68.       Consider the following LPP :
Max Z=15x1+10x2
Subject to the constraints
4x1+6x2 ≤ 360
3x1+0x2 ≤ 180
0x1+5x2 ≤ 200
x1, x2 ≥ 0
The solution of the LPP using Graphical solution technique is :
(1) x1=60, x2=0 and Z=900
(2) x1=60, x2=20 and Z=1100
(3) x1=60, x2=30 and Z=1200
(4) x1=50, x2=40 and Z=1150
Answer: 2
69.       Consider the following LPP :
Min Z=2x1+x2+3x3
Subject to :
x1−2x2+x3 ≥ 4
2x1+x2+x3 ≤ 8
x1−x3 ≥ 0
x1, x2, x3 ≥ 0
The solution of this LPP using Dual Simplex Method is :
(1) x1=0, x2=0, x3=3 and Z=9
(2) x1=0, x2=6, x3=0 and Z=6
(3) x1=4, x2=0, x3=0 and Z=8
(4) x1=2, x2=0, x3=2 and Z=10
Answer: 3
70.    Consider a Takagi - Sugeno - Kang (TSK) Model consisting of rules of the form :
If x1 is Ai1 and ... and xr is Air
THEN y =fi(x1, x2, ..., xr) = bi0+bi1 x1+...+bir xr
assume, αi is the matching degree of rule i, then the total output of the model is given by:
Answer: 2

Thursday, 30 November 2017

51.       User level threads are threads that are visible to the programmer and are unknown to the kernel. The operating system kernel supports and manages kernel level threads. Three different types of models relate user and kernel level threads.
Which of the following statements is/are true?
(a) (i) The Many - to - one model maps many user threads to one kernel thread
     (ii) The one - to - one model maps one user thread to one kernel thread
     (iii) The many - to - many model maps many user threads to smaller or equal kernel
threads
(b)  (i) Many - to - one model maps many kernel threads to one user thread
      (ii) One - to - one model maps one kernel thread to one user thread
      (iii) Many - to - many model maps many kernel threads to smaller or equal user
threads
Code :
(1) (a) is true; (b) is false
(2) (a) is false; (b) is true
(3) Both (a) and (b) are true
(4) Both (a) and (b) are false
Answer: 1
52.       Consider a system with five processes P0 through P4 and three resource types A, B and C. Resource type A has seven instances, resource type B has two instances and resource type C has six instances suppose at time T0 we have the following allocation.
If we implement Deadlock detection algorithm we claim that system is ..................
(1) Semaphore
(2) Deadlock state
(3) Circular wait
(4) Not in deadlock state
Answer: 4
53.       Consider a disk queue with requests for I/O to blocks on cylinders 98, 183, 37, 122, 14, 124, 65, 67. Suppose SSTF disk scheduling algorithm implemented to meet the requests then the total number of head movements are ................... if the disk head is initially at 53.
(1) 224
(2) 248
(3) 236
(4) 240
Answer: 3
54.       The Bounded buffer problem is also known as ..................
(1) Producer - consumer problem
(2) Reader - writer problem
(3) Dining Philosophers problem
(4) Both (2) and (3)
Answer: 1
55.       In Artificial Intelligence (AI), which agent deals with happy and unhappy state?
(1) Simple reflex agent
(2) Model based agent
(3) Learning agent
(4) Utility based agent
Answer: 4
56.       If b is the branching factor and m is the maximum depth of the search tree, what is the space complexity of greedy search?
(1) O(b+m)
(2) O(bm)
(3) O(bm)
(4) O(mb)
Answer: 3
57.       Let P, Q, R and S be Propositions. Assume that the equivalences P(Q¬Q) and QR hold. Then the truth value of the formula (PQ)((PR)S) is always :
(1) True
(2) False
(3) Same as truth table of Q
(4) Same as truth table of S
Answer: 1
58.       “If X, then Y unless Z” is represented by which of the following formulae in propositional
logic?
(1) (X Y) → ¬ Z
(2) (X ¬ Z) → Y
(3) X → (Y ¬ Z)
(4) Y → (X ¬ Z)
Answer: 2
59.       Consider the following two well-formed formulas in prepositional logic.
F1 : P ¬ P
F2 : (P ¬ P) (¬ P P)
Which of the following statements is correct?
(1) F1 is Satisfiable, F2 is valid
(2) F1 is unsatisfiable, F2 is Satisfiable
(3) F1 is unsatisfiable, F2 is valid
(4) F1 and F2 both are Satisfiable
Answer: 1
60.    Standard planning algorithms assume environment to be .................
(1) Both deterministic and fully observable
(2) Neither deterministic nor fully observable
(3) Deterministic but not fully observable
(4) Not deterministic but fully observable
Answer: 1

Wednesday, 29 November 2017

41.       Which of the following statements is/are TRUE regarding JAVA?
(a) Constants that cannot be changed are declared using the ‘static’ keyword.
(b) A class can only inherit one class but can implement multiple interfaces.
Code :
(1) Only (a) is TRUE.
(2) Only (b) is TRUE.
(3) Both (a) and (b) are TRUE.
(4) Neither (a) nor (b) is TRUE.
Answer: 2
42.       What is the output of the following JAVA program?
Class Test
{
public static void main (String [ ] args)
{
Test obj = new Test ( );
obj.start ( );
}
void start ( )
{
String stra=”do”;
String strb = method (stra);
System.out.print(“:” + stra + strb);
}
String method (String stra)
{
stra=stra+”good”;
System.out.print (stra);
return “good”;
}
}
(1) dogood : dogoodgood
(2) dogood : gooddogood
(3) dogood : dodogood
(4) dogood : dogood
Answer: 4
43.       Statistical software quality assurance in software engineering involves ................
(1) using sampling in place of exhaustive testing of software.
(2) surveying customers to find out their opinions about product quality.
(3) tracing each defect to its underlying cause, isolating the vital few causes, and moving to correct them.
(4) tracing each defect to its underlying causes, and using the Pareto principle to correct each problem found.
Answer: 3
44.       Which of the following statements is/are FALSE with respect to software testing?
S1 : White-box tests are based on specifications; better at telling whether program meets specification, better at finding errors of ommission.
S2 : Black-box tests are based on code; better for finding crashes, out of bounds errors, file not closed errors.
S3 : Alpha testing is conducted at the developer’s site by a team of highly skilled testers for software that is developed as a product to be used by many customers.
(1) Only S1 and S2 are FALSE.
(2) Only S1 and S3 are FALSE.
(3) Only S2 and S3 are FALSE.
(4) All of S1, S2, and S3 are FALSE.
Answer: 1
45.       A signal processor software is expected to operate for 91.25 days after repair, and the mean software repair time is expected to be 5 minutes. Then, the availability of the software is :
(1) 96.9862%
(2) 97.9862%
(3) 98.9962%
(4) 99.9962%
Answer: 4
46.       Consider the method mcq ( ) :
int mcq (boolean a, boolean b, boolean c, boolean d)
{
int ans=1;
if (a) {ans = 2;}
else if (b) {ans = 3;}
else if (c) {
if (d) {ans=4;}
}
return ans ;
}
If
M1 = Number of tests to exhaustively test mcq ( );
M2 = Minimum number of tests to achieve full statement coverage for mcq ( ); and
M3 = Minimum number of tests to achieve full branch coverage for mcq ( );
then (M1, M2, M3) = ....................
(1) (16, 3, 5)
(2) (8, 5, 3)
(3) (8, 3, 5)
(4) (16, 4, 4)
Answer:
47.       A simple stand - alone software utility is to be developed in ’C’ programming by a team of software experts for a computer running Linux and the overall size of this software is estimated to be 20,000 lines of code. Considering (a, b) = (2.4, 1.05) as multiplicative and exponention factor for the basic COCOMO effort estimation equation and (c, d)=(2.5, 0.38) as multiplicative and exponention factor for the basic COCOMO development time estimation equation, approximately how long does the software project take to complete?
(1) 10.52 months
(2) 11.52 months
(3) 12.52 months
(4) 14.52 months
Answer: 2
48.       In Software Configuration Management (SCM), which of the following is a use-case supported by standard version control systems?
(a) Managing several versions or releases of a software
(b) Filing bug reports and tracking their progress
(c) Allowing team members to work in parallel
(d) Identifying when and where a regression occurred
Code :
(1) Only (a), (c), and (d)
(2) Only (a), (b), and (c)
(3) Only (a), (b), and (d)
(4) Only (b), (c), and (d)
Answer: 3
49.       Consider the following four processes with the arrival time and length of CPU burst given in
milliseconds :
Process              Arrival Time  Burst Time
P1                       0                      8
P2                       1                      4
P3                       2                      9
P4                       3                      5
The average waiting time for preemptive SJF scheduling algorithm is .................
(1) 6.5 ms
(2) 7.5 ms
(3) 6.75 ms
(4) 7.75 ms
Answer: 1
50.    Consider a virtual page reference string 7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2, 1, 2, 0, 1, 7, 0, 1. Suppose a demand paged virtual memory system running on a computer system such that the main memory has 3 page frames. Then ................. page replacement algorithm has minimum number of page faults.
(1) FIFO
(2) LIFO
(3) LRU
(4) Optimal
Answer: 4