December 2013 UGC NET Computer Science Solved Paper II
1. When
data and acknowledgement are sent in the same frame, this is called as
(A) Piggy packing (B) Piggy backing
(C) Back packing (D) Good packing
Answer: B
2. Encryption
and Decryption is the responsibility of ............... Layer.
(A) Physical (B)
Network
(C) Application (D) Datalink
Answer: C
3. An
analog signal carries 4 bits in each signal unit. If 1000 signal units are sent
per second, then baud rate and bit rate of the signal are ............... and
..............
(A) 4000 bauds \ sec & 1000 bps
(B) 2000 bauds \ sec & 1000 bps
(C) 1000 bauds \ sec & 500 bps
(D) 1000 bauds \ sec & 4000 bps
Answer: D
Explanation:
Bit rate is the number of bits per second.
Baud rate is the number of signal units per second. Baud rate is less than or
equal to the bit rate.
Baud rate = 1000 bauds per second (baud/s)
Bit rate = 1000 x 4 = 4000 bps
4. The
VLF and LF bauds use .............. propagation for communication.
(A) Ground (B)
Sky
(C) Line of sight (D) Space
Answer: A
5. Using
the RSA public key crypto system, if p=13, q=31 and d=7, then the value of e is
(A) 101 (B)
105
(C) 103 (D)
107
Answer: C
Explanation:
Basic RSA Algorithm:
1. Choose two primes, p & q.
2. Compute n=p*q and z=(p-1)*(q-1).
3. Choose a number relatively prime to z and
call it d.
4. Find e such that e*d=1modz.
Given p=13, q=31 & d=7, e=?
n=p*q=403
z=(p-1)(q-1)=360
e*d=1modz
7e=1mod360, then 7e must be 361, 721, 1081,
1441, etc. Dividing each of these in turn by 7 to see which is divisible by 7,
we find that 721/7 = 103, hence e = 103.
6. FAN IN of a component A is defined as
(A) Number of components that can call or
pass control to component A.
(B) Number of components that are called by
component A.
(C) Number of components related to component
A.
(D) Number of components dependent on
component A.
Answer: A
7. The
relationship of data elements in a module is called
(A) Coupling (B)
Modularity
(C) Cohesion (D)
Granularity
Answer: C
8. Software
Configuration Management is the discipline for systematically controlling
(A) the changes due to the evolution of work
products as the project proceeds.
(B) the changes due to defects (bugs) being
found and then fixed.
(C) the changes due to requirement changes
(D) all of the above
Answer: D
9. Which
one of the following is not a step of requirement engineering ?
(A) Requirement elicitation
(B) Requirement analysts
(C) Requirement design
(D) Requirement documentation
Answer: C
10. Testing
of software with actual data and in actual environment is called
(A) Alpha testing (B) Beta testing
(C) Regression testing (D) None of the above
Answer: B
11. The
student marks should not be greater than 100. This is
(A) Integrity constraint
(B) Referential constraint
(C) Over-defined constraint
(D) Feasible constraint
Answer: A
12. GO
BOTTOM and SKIP-3 commands are given one after another
in a database file of 30 records. It shifts the control to
(A) 28th record (B) 27th record
(C) 3rd record (D) 4th record
Answer: D
13. An
ER Model includes
I. An
ER diagram portraying entity types.
II. Attributes for each entity type
III. Relationships among entity types.
IV. Semantic integrity constraints that
reflects the business rules about data not captured in the ER diagram.
(A) I, II, III & IV (B) I&IV
(C) I, II & IV (D) I & III
Answer: A
14. Based
on the cardinality ratio and participation ............... associated with a
relationship type, choose either the Foreign Key Design, the Cross Referencing
Design or Mutual Referencing Design.
(A) Entity (B)
Constraints
(C) Rules (D)
Keys
Answer: B
15. Data
Integrity control uses ................
(A) Upper and lower limits on numeric data.
(B) Passwords to prohibit unauthorised access
to files.
(C) Data dictionary to keep the data
(D) Data dictionary to find last access of
data
16. What
does the following declaration mean ?
int (*ptr) [10];
(A) ptr is an array of pointers of 10 integers.
(B) ptr is a pointer to an array of 10
integers.
(C) ptr is an array of 10 integers.
(D) none of the above.
Answer: B
17. Which
of the following has compilation error in C ?
(A) int n = 32;
(B) char ch = 65;
(C) float f= (float) 3.2;
(D) none of the above
Answer: D
18. Which
of the following operators cannot be overloaded in C+ + ?
(A) * (B)
+=
(C) == (D)
::
Answer: D
19. ..................
allows to create classes which are derived from other classes, so that they
automatically include some of its "parent's" members, plus its own
members.
(A) Overloading (B) Inheritance
(C) Polymorphism (D) Encapsulation
Answer: B
20. The
correct way to round off a floating number x to an integer value is
(A) y = (int)(x+0.5)
(B) y = int(x+0.5)
(C) y = (int)x+0.5
(D) y = (int)((int)x+0.5)
Answer: B
21. What
is the value of the postfix expression ?
a b c d + - * (where a = 8, b = 4, c = 2 and
d = 5)
(A) -3/8 (B)
-8/3
(C) 24 (D)
-24
Answer: D
22. If
the queue is implemented with a linked list, keeping track of a front pointer
and a rear pointer, which of these pointers will change during an insertion
into a non-empty queue?
(A) Neither of the pointers change
(B) Only front pointer changes
(C) Only rear pointer changes
(D) Both of the pointers changes
Answer: C
23. ...............
is often used to prove the correctness of a recursive function.
(A) Diagonalization
(B) Communitivity
(C) Mathematical Induction
(D) Matrix Multiplication
Answer: C
24. For
any B-tree of minimum degree t ≥2, every node other than the root must have atleast
............... keys and every node can have at most .............. keys.
(A) t-1, 2t+1 (B)
t+1, 2t+1
(C) t-1, 2t-1 (D)
t+1, 2t-1
Answer: C
25. Given
two sorted list of size 'm' and 'n' respectively. The number of comparison
needed in the worst case by the merge sort algorithm will be
(A) m x n (B)
max (m, n)
(C) min (m, n) (D) m + n – 1
26. Given
the following statements :
S1 : SLR uses follow information
to guide reductions. In case of LR and LALR parsers, the look-aheads are
associated with the items and they make use of the left context available to
the parser.
S2 : LR grammar is a larger sub-class
of context free grammar as compared to that SLR and LALR grammars.
Which of the following is true ?
(A) S1 is not correct and S2
is not correct.
(B) S1 is not correct and S2
is correct.
(C) S1 is correct and S2
is not correct.
(D) S1 is correct and S2
is correct.
Answer: C
27. The
context free grammar for the language
L = {an bm | n≤m+3, n≥0,
m≥0} is
(A) S→aaaA; A→aAb|B, B→Bb|λ
(B) S→aaaA|λ, A→aAb|B, B→Bb|λ
(C) S→aaaA|aaA|λ, A→aAb|B, B→Bb|λ
(D) S→aaaA|aaA|aA|λ, A→aAb|B, B→Bb|λ
Answer: C
28. Given
the following statements :
S1 : If L is a regular language
then the language {uv | uϵL, vϵLR} is also regular.
S2 : L = {wwR} is
regular language.
Which of the following is true ?
(A) S1 is not correct and S2
is not correct.
(B) S1 is not correct and S2
is correct.
(C) S1 is correct and S2
is not correct.
(D) S1 is correct and S2
is correct.
Answer: D
29. The
process of assigning load addresses to the various parts of the program and adjusting
the code and data in the program to reflect the assigned addresses is called
..................
(A) Symbol resolution (B) Parsing
(C) Assembly (D)
Relocation
Answer: D
30. Which
of the following derivations does a top-down parser use while parsing an input
string ? The input is scanned from left to right.
(A) Leftmost derivation
(B) Leftmost derivation traced out in reverse
(C) Rightmost derivation traced out in
reverse
(D) Rightmost derivation
Answer: A
31. The
dual of a Boolean expression is obtained by interchanging
(A) Boolean sums and Boolean products
(B) Boolean sums and Boolean products or
interchanging 0's and 1's
(C) Boolean sums and Boolean products and interchanging
0's & 1's
(D) Interchanging 0's and 1's
Answer: C
32. Given
that (292)10 = (1204)x in some number system x. The base
x of that number system is
(A) 2 (B)
8
(C) 10 (D)
None of the above
Answer: D
Explanation:
6|292
6|48|4
6|8|0
6|1|2
6|1|1
Solution: (1204)6
So here, x=6
33. The
sum of products expansion for the function
F(x, y, z) = (x + y)z’ is given as
(A) x’y’z + xyz’ + x’yz’
(B) xyz + xyz’ + xy’z’
(C) xy’z’ + x’y’z’ + xyz’
(D) xyz’ + xy’z’ + x’yz’
Answer: D
Explanation:
Use Boolean identities to expand the product
and simplify.
F(x, y, z)=(x + y)z’
=xz’+yz’ Distributive
law
=x1z’+1yz’ Identity law
=x(y+y’)z’+(x+x’)yz’ Unit property
=xyz’+xy’z’+xyz’+x’yz’ Distributive law
=xyz’+xy’z’+x’yz’ Idempotent law
34. Let
P(m, n) be the statement
"m divides n" where the universe of
discourse for both the variables is the set of positive integers. Determine the
truth values of each of the following propositions:
I. ∀m ∀n P(m,n),
II. ∃m
∀n P(m, n)
(A) Both I and II are true
(B) Both I and II are false
(C) I - false & II - true
(D) I - true & II – false
Answer: C
35. Big
- O estimate for
f(x) = (x + 1) log(x2 + 1) + 3x2
is given as
(A) O(xlogx) (B)
O(x2)
(C) O(x3) (D) O(x2logx)
Answer: B
Explanation:
Big-O notation of f(x)=(x+1) log(x2+1)
+ 3x2
Note (x+1) is O(x) and x2+1≤2x2
when x>1
So,
log x2+1≤log(2x2)=log 2+ log x2=log 2+ 2 log x
≤
3 log x if x >2
Thus, log x2+1 is O(log x)
The first part of f(x) is O(x log x)
Also, 3x2 is O(x2)
36. How
many edges are there in a forest of t-trees containing a total of n vertices ?
(A) n+t (B)
n-t
(C) n*t (D)
nt
Answer: B
37. Let
f and g be the functions from the set of integers to the set integers defined
by
f(x) = 2x + 3 and g(x) = 3x + 2
Then the composition of f and g and g and f
is given as
(A) 6x + 7, 6x + 11
(B) 6x + 11, 6x + 7
(C) 5x + 5, 5x + 5
(D) None of the above
Answer: A
Explanation:
fog(x)=f(g(x))=f(3x+2)=2(3x+2)+3=6x+7
gof(x)=g(f(x))=g(2x+3)=3(2x+3)+2=6x+11
38. If
n and r are non-negative integers and n≥r, then p(n + 1, r) equals to
(A) P(n,r)(n+1) / (n+1-r)
(B) P(n,r)(n+1) / (n-1+r)
(C) p(n,r)(n-1) / (n+1-r)
(D) p(n,r)(n+1) / (n+1+r)
Answer: A
39. A
graph is non-planar if and only if it contains a subgraph homeomorphic to
(A) K3,2 or K5 (B) K3,3 and K6
(C) K3,3 or K5 (D) K2,3 and K5
Answer: C
Explanation:
Kuratowski’s Theorem:
A graph is non-planar if and only if it contains a subgraph that is
homeomorphic to either K5 or K3,3.
40. Which
of the following statements are true ?
I. A
circuit that adds two bits, producing a sum bit and a carry bit is called half
adder.
II. A
circuit that adds two bits, producing a sum bit and a carry bit is called full
adder.
III. A circuit that adds two bits and a carry
bit producing a sum bit and a carry bit is called full adder.
IV. A
device that accepts the value of a Boolean variable as input and produces its complement
is called an inverter.
(A) I & II (B) II & III
(C) I, II, III (D) I, III & IV
Answer: D
41. Active
X controls are Pentium binary programs that can be embedded in ...............
(A) Word pages (B) URL pages
(C) Script pages (D) Web pages
Answer: D
42. Match
the following :
List-I List
- II
a. Wireless Application Environment i. HTTP
b. Wireless Transaction Protocol ii. IP
c. Wireless Datagram Protocol iii. Scripts
d. Wireless iv.
UDP
Codes :
a b
c d
(A) ii
iv i
iii
(B) iv
iii ii i
(C) iv
iii i ii
(D) iii
i iv ii
Answer: D
43. Which
of the following is widely used inside the telephone system for long-haul data traffic
?
(A) ISDN (B)
ATM
(C) Frame Relay (D) ISTN
Answer: B
44. The
document standards for EDI were first developed by large business house during
the 1970s and are now under the control of the following standard organisation:
(A) ISO (B)
ANSI
(C) ITU-T (D)
IEEE
Answer: B
45. Electronic
Data Interchange Software consists of the following four layers:
(A) Business application, Internal format
conversion, Network translator, EDI envelope
(B) Business application, Internal format
conversion, EDI translator, EDI envelope
(C) Application layer, Transport layer, EDI
translator, EDI envelope
(D) Application layer, Transport layer, IP
layer, EDI envelope
46. Consider
a preemptive priority based scheduling algorithm based on dynamically changing priority.
Larger priority number implies higher priority. When the process is waiting for
CPU in the ready queue (but not yet started execution), its priority changes at
a rate a = 2. When it starts running, its priority changes at a rate b = 1. All
the processes are assigned priority value 0 when they enter ready queue. Assume
that the following processes want to execute :
Process Arrival Service
ID Time Time
P1 0 4
P2 1 1
P3 2 2
P4 3 1
The time quantum q = 1. When two processes
want to join ready queue simultaneously, the process which has not executed
recently is given priority. The finish time of processes P1, P2, P3 and P4 will
respectively be
(A) 4, 5, 7 and 8
(B) 8, 2, 7 and 5
(C) 2, 5, 7 and 8
(D) 8, 2, 5 and 7
Answer: D
47. The
virtual address generated by a CPU is 32 bits. The Translation Look-aside
Buffer (TLB) can hold total 64 page table entries and a 4-way set associative
(i.e. with 4- cache lines in the set). The page size is 4 KB. The minimum size
of TLB tag is
(A) 12 bits (B)
15 bits
(C) 16 bits (D)
20 bits
Answer: C
Explanation:
VirtualAddress = 32 bits
PageSize = 4KB = 12 bits
therefore : VPNTag = 20 bits, OffsetTag = 12
bits
TLBEntryLength = VPNTag = 20 bits
TotalTLBEntries = 64,
4-way implies 64/ 4 = 16 sets = 4 bits
therefore : TLBIndex = 4 bits
TLBTag = TLBEntryLength - TLBIndex = 20 - 4 =
16 bits
48. Consider
a disk queue with request for input/output to block on cylinders
98, 183, 37, 122, 14, 124, 65, 67
in that order. Assume that disk head is
initially positioned at cylinder 53 and moving towards cylinder number 0. The
total number of head movements using Shortest Seek Time First (SSTF) and SCAN
algorithms are respectively
(A) 236 and 252 cylinders
(B) 640 and 236 cylinders
(C) 235 and 640 cylinders
(D) 235 and 252 cylinders
Answer: 236 and 208 cylinders
Explanation:
SSTF
Initial head position =53
The closest queue to initial head position=65
head moves from 53 to 65=12
head moves from 65 to 67=2
head moves from 67 to 37=30
head moves from 37 to 14=23
head moves from 14 to 98=84
head moves from 98 to 122=24
head moves from 122 to 124=2
head moves from 124 to 183=59
Total head movement=236
SCAN
Initial head position=53 and moving towards 0
head moves from 53 to 37=16
head moves from 37 to 14=23
head moves from 14 to 65=51
head moves from 65 to 67=2
head moves from 67 to 98=31
head moves from 98 to 122=24
head moves from 122 to 124=2
head moves from 124 to 183=59
Total head movement=208
49. How
much space will be required to store the bit map of a 1.3 GB disk with 512
bytes block size ?
(A) 332.8 KB (B)
83.6 KB
(C) 266.2 KB (D)
256.6 KB
Answer: A
Explanation:
block size=29bytes (512 bytes)
disk size=1.3x230bytes (1.3 GB)
n=1.3x230/29=1.3x221
bits=1.3x210x28x23 bits=1.3x28 Kilo
Bytes=332.8 KB
50. Linux
operating system uses
(A) Affinity Scheduling
(B) Fair Preemptive Scheduling
(C) Hand Shaking
(D) Highest Penalty Ratio Next
Answer: B
