Tuesday, 24 January 2017

CBSE UGC NET Computer Science Paper II January 2017 - Part 4

31.       Which of the following strings would match the regular expression: p+[3-5]*[xyz]?
I. p443y
Il. p6y
III. 3xyz
IV. p35z
V. p353535x
Vl. ppp5
(1) I, III and Vl only
(2) IV, V and VI only
(3) II, IV and V only
(4) I, IV and V only
Answer: 4
32.       Consider the following assembly language instructions:
mov al, 15
mov ah, 15
xor al, al
mov cl, 3
shr ax, cl
add al, 90H
adc ah, 0
What is the value in ax register after execution of above instructions?
(1) 0270H
(2) 0170H
(3) 01E0H
(4) 0370H
Answer: 1
33.       Consider the following statements related to compiler construction:
I. Lexical Analysis is specified by context-free grammars and implemented by pushdown automata.
II. Syntax Analysis is specified by regular expressions and implemented by finite-state machine.
Which of the above statement(s) is/are correct?
(1) Only l
(2) Only ll
(3) Both I and II
(4) Neither I nor Il
Answer: 4
34.       The contents of Register (BL) and Register (AL) of 8085 microprocessor are 49H and 3AH respectively. The contents of AL, the status of carry flag (CF) and sign flag (SF) after executing 'SUB AL, BL' assembly language instruction, are
(1) AL=0FH; CF=1; SF=1
(2) AL=F0H; CF=0; SF=0
(3) AL=F1H; CF=1; SF=1
(4) AL=1FH; CF=1; SF=1
Answer: 1
35.       Which of the following statement(s) regarding a linker software is/are true?
I. A function of a linker is to combine several object modules into a single load module.
II. A function of a linker is to replace absolute references in an object module by symbolic references to locations in other modules.
(1) Only I
(2) Only II
(3) Both I and II
(4) Neither I nor Il
Answer: 3

36.       There are three processes P1, P2 and P3 sharing a semaphore for synchronising a variable. Initial value of semaphore is one. Assume that negative value of semaphore tells us how many processes are waiting in queue. Processes access the semaphore in following order:
(a) P2 needs to access
(b) P1 needs to access
(c) P3 needs to access
(d) P2 exits critical section
(e) Pi exits critical section
The final value of semaphore will be:
(1) 0
(2) 1
(3) -1
(4) -2
Answer: 1
37.       In a paging system, it takes 30 ns to search translation Look-aside Buffer (TLB) and 90 ns to access the main memory. If the TLB hit ratio is 70%, the effective memory access time is:
(1) 48 ns
(2) 147 ns
(3) 120 ns
(4) 84 ns
Answer: 2
38.       Match the following w.r.t. Input/Output management:
List-l                              List-II
a. Device controller     i. Extracts information from the
controller register and store it
in data buffer
b. Device driver            ii. I/O scheduling
c. Interrupt handler      iii. Performs data transfer
d. Kernel I/O subsystem iv. Processing of I/O request
     a   b   c   d
(1) iii  iv   i   ii
(2) ii   i    iv  iii
(3) iv  i    ii   iii
(4) i   iii   iv   ii
Answer: 4
39.       Which of the following scheduling algorithms may cause starvation?
a. First-come-first-served
b. Round Robin
c. Priority
d. Shortest process next
e. Shortest remaining time first
(1) a, c and e
(2) c, d and e
(3) b, d and e
(4) b, c and d
Answer: 2
40.    Distributed operating systems consist of:
(1) Loosely coupled O.S. software on a loosely coupled hardware
(2) Loosely coupled O.S. software on a tightly coupled hardware
(3) Tightly coupled O.S. software on a loosely coupled hardware
(4) Tightly coupled O.S. software on a tightly coupled hardware
Answer: 1

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