# Recent questions tagged virtual-gate-test-series

1 vote
1 answer
1
Consider the code fragment: count = 3; S1; Fork L1; L1: S3; S2; goto L3; S4; Fork L2; L2: S6; goto L3; S5; L3: join count S7 Which one of the following represents correct precedence graph of the above code fragment? the answer is given but I’m getting where am I wrong?
0 votes
1 answer
2
how many tables are required?
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3
A' is set of all possible schedules 'C' is set of all possible schedules that are guaranteed to produce a correct final result 'S' is the set of all serializable schedules 'P' is the set of all schedules possible under 2-phase locking protocol Which is FALSE? $P\subseteq C$ $S\subset P$ $S\subseteq P$ $P\subset C$
2 votes
1 answer
4
How many possible finite automata ( DFA ) are there with two states X and Y, where X is always initial state with alphabet a and b, that accepts everything? answer is 20 or 64?
0 votes
2 answers
5
If $L = \Bigl \{ x \mid x \in \{ a, b, c \}^*, \text{The length of$x$is a square } \Bigr \}$ then $L$ is Regular Recursive but not context free Context Free but not regular None of the above
0 votes
2 answers
6
Which of the following is/are true? I. Every strict schedule is cascade less schedule and recoverable schedule II. Every cascade less schedule is recoverable schedule III. Every cascading rollback schedule is recoverable schedule IV. Every cascading rollback schedule is a strict schedule V. Every ... schedule All of the above I, II, and IV only II, III, IV, and V only I, II, and III only
0 votes
1 answer
7
Let Σ = {a, b}. For a word w ∈ Σ* , let na(x) denote the number of a’s in w and let nb(x) denote the number of b’s in w. Consider the following language: L := {xy | x, y ∈ Σ* , na(x) = nb(y)} What can we say about L? L is regular, but not context-free. L is context-free, but not regular. L is Σ*. None of these.
1 vote
1 answer
8
Consider the unpipelined machine with $10$ nanoseconds clock cycles. It uses four cycles for ALU operations and branch whereas 5 cycles for memory operation. Assume that the relative frequencies of these operations are $40\%, 20\%,$ and $40\%$ respectively. ... adds $1$ nanosecond overhead to the clock. _____________ times speed up in the instruction execution rate is gained from a pipeline.
0 votes
1 answer
9
1 vote
1 answer
10
Let $G$ be a graph on $n$ vertices with $4n-16$ edges.Consider the following: 1. There is a vertex of degree smaller than $8$ in $G.$ 2. There is a vertex such that there are less than $16$ vertices at a distance exactly $2$ from it. Which of the following is TRUE: 1 only 2 only Both 1 and 2 Neither 1 nor 2
1 vote
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11
For a binary string, $x = a_0,a_1, · · · ,a_n−1$ define $val(x)$ to be the value of x interpreted as a binary number, where $a_0$ is the most significant bit. More formally, $val(x)$ is given by $\sum_{0\leq i<n}2^{n-1-i}\cdot a_{i}$ How many minimum states will be in a finite automaton that accepts exactly the set of binary strings x such that val(x) is divisible by either $4$ or $5?$
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12
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13
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14
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15
2 votes
1 answer
16
Consider the following two statements$:$ The two graphs $G_{1}$ and $G_{2}$ are isomorphic Each of $G_{1}$ and $G_{2}$ are self-dual. Both $(i)$ and $(ii)$ are true Only $(i)$ is true Only $(ii)$ is true Both $(i)$ and $(ii)$ are false
0 votes
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17
i have solved it by putting the values
2 votes
2 answers
18
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19
0 votes
1 answer
20
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21
0 votes
1 answer
22
An array of $n$ distinct elements is said to be un-sorted if for every index $i$ such that $2 ≤ i ≤ n − 1,$ either $\{A[i] > max{A[i − 1], A[i + 1]}\},$ or $\{A[i] < min{A[i − 1], A[i + 1]}\}.$ What is the time-complexity of the fastest algorithm that takes as input a sorted array $A$ ... $O(n)$ $(B) O(n)$ but not $O( \sqrt{n})$ $(C) O( \sqrt{n})$ but not $O(log n)$ $(D) O(log n)$ but not $O(1)$
0 votes
1 answer
23
Consider the grammar given $S\rightarrow AA$ $A\rightarrow aA / b$ How many entries will be blank in the GOTO table for SR(0) items?
1 vote
1 answer
24
Which of the following statements are correct regarding subnet mask $255.255.240.0?$ i. Class A network subnet mask$: 4096$ subnets and $4096$ systems per subnetwork ii. Class B network subnet mask$: 16$ subnets and $4096$ systems per subnetwork iii. Class C network subnet mask$: 1$ subnet and $256$ systems per subnetwork All are correct i, ii i, iii ii, iii
1 vote
0 answers
25
$\int \limits_0^1 (1 + y^2)^{-1.5} dy=?$
0 votes
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26
Which of the following statements is TRUE about the propositional logic formula $S:\{(p→q)∧(¬q∨r)∧(r→s)\}→¬(p→s)$ $(A)$ S is a contradiction $(B)$ S is satisfiable but not valid $(C)$ S is valid $(D)$ None of the above
3 votes
2 answers
27
Let $L$ be a given context-free language over the alphabet $\{a, b\}$. Construct $L1, L2$ as follows. Let $L1 = L − \{xyx \mid x, y \in \{a, b\}^*\}$, and $L2 = L·L$. Then, Both $L1$ and $L2$ are regular. Both $L1$ and $L2$ are context-free but not necessarily regular. $L1$ is regular and $L2$ is context-free. $L1$ and $L2$ both may not be context-free.
1 vote
0 answers
28
If $h$ represents the Homomorphic image of a string and $h^{-1}$ represent the Inverse Homomorphic image of a string. We have a language $L$, $(A)\ h(h^{-1}(L)) = L$ $(B)\ h(h^{-1}(L)) \subset L$ $(C)\ h(h^{-1}(L)) \subset L$ $(D)\ None$ Some reference given here, but I am not able to understand: https://courses.engr.illinois.edu/cs373/sp2013/Lectures/lec08.pdf (5th page)
1 vote
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29
Consider the following instance R. A 1 2 3 4 B Null 1 2 2 The number of tuples returned by the following SQL query is _____________. > select * from R as R1 where not exists (select * from R) where B = R1.A
1 vote
1 answer
30
What would be SDT for this I want to verify the answer.