31.
Shift-Reduce
parsers perform the following :
(A) Shift step that
advances in the input stream by K(K>1) symbols and Reduce step that applies
a completed grammar rule to some recent parse trees, joining them together as
one tree with a new root symbol.
(B) Shift step that
advances in the input stream by one symbol and Reduce step that applies a completed
grammar rule to some recent parse trees, joining them together as one tree with
a new root symbol.
(C) Shift step that
advances in the input stream by K(K = 2) symbols and Reduce step that applies a
completed grammar rule to form a single tree.
(D) Shift step that does
not advance in the input stream and Reduce step that applies a completed
grammar rule to form a single tree.
Answer: B
32.
Which of
the following is true ?
(A) Canonical LR parser
is LR (1) parser with single look ahead terminal
(B) All LR(K) parsers
with K > 1 can be transformed into LR(1) parsers.
(C) Both (A) and (B)
(D) None of the above
Answer: C
33.
In a
two-pass assembler, symbol table is
(A) Generated in first
pass
(B) Generated in second
pass
(C) Not generated at all
(D) Generated and used
only in second pass
Answer: A
34.
Debugger is a
program that
(A) allows to examine
and modify the contents of registers
(B) does not allow
execution of a segment of program
(C) allows to set
breakpoints, execute a segment of program and display contents of
register
(D) All of the above
Answer: C
35.
The
following Context-Free Grammar (CFG) :
S®aB | bA
A®a | as | bAA
B®b | bs | aBB
will generate
(A) odd numbers of a’s
and odd numbers of b’s
(B) even numbers of a’s
and even numbers of b’s
(C) equal numbers of a’s
and b’s
(D) different numbers of
a’s and b’s
Answer: A,B,C,D
36.
Consider the
following justifications for commonly using the two-level CPU scheduling :
I. It is used when
memory is too small to hold all the ready processes.
II. Because its
performance is same as that of the FIFO.
III. Because it
facilitates putting some set of processes into memory and a choice is made from
that.
IV. Because it does not
allow to adjust the set of in-core processes.
Which of the following
is true ?
(A) I, III and IV (B) I and II
(C) III and IV (D) I and III
Answer: D
37.
A
specific editor has 200 K of program text, 15 K of initial stack, 50 K of
initialized data, and 70 K of bootstrap code. If five editors are started
simultaneously, how much physical memory is needed if shared text is used ?
(A) 1135 K (B) 335 K
(C) 1065 K (D) 320 K
Answer: B
38.
Which of
the following conditions does not hold good for a solution to a critical
section problem ?
(A) No assumptions may
be made about speeds or the number of CPUs.
(B) No two processes may
be simultaneously inside their critical sections.
(C) Processes running
outside its critical section may block other processes.
(D) Processes do not
wait forever to enter its critical section.
Answer: C
39.
For the
implementation of a paging scheme, suppose the average process size be x bytes,
the page size be y bytes, and each page entry requires z bytes. The optimum
page size that minimizes the total overhead due to the page table and the
internal fragmentation loss is given by
(A) x/2
(B) xz/2
(C) √2xz
(D) (√xz)/2
Answer: C
40.
In a demand paging memory system, page table is held in
registers. The time taken to service a page fault is 8 m.sec. if an empty frame
is available or if the replaced page is not modified, and it takes 20 m.secs.,
if the replaced page is modified. What is the average access time to service a
page fault assuming that the page to be replaced is modified 70% of the time ?
(A) 11.6 m.sec. (B) 16.4 m.sec.
(C) 28 m.sec. (D) 14 m.sec.
Answer: B
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