# Recent activity by Nit9

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A disk has $8$ equidistant tracks. The diameters of the innermost and outermost tracks are $1$ cm and $8$ cm respectively. The innermost track has a storage capacity of $10$ MB. If the disk has $20$ sectors per track and is currently at the end of the $5^{th}$ sector of the inner- ... contiguous data starting from the sector $4$ of the outer-most track? $13.5 \ ms$ $10 \ ms$ $9.5 \ ms$ $20 \ ms$
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The storage area of a disk has the innermost diameter of $10$ cm and outermost diameter of $20$ cm. The maximum storage density of the disk is $1400$ bits/cm. The disk rotates at a speed of $4200$ RPM. The main memory of a computer has $64$-bit word length and $1$µs ... data transfer from the disk, the percentage of memory cycles stolen for transferring one word is $0.5 \%$ $1 \%$ $5\%$ $10\%$
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The essential content(s) in each entry of a page table is / are Virtual page number Page frame number Both virtual page number and page frame number Access right information
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Consider the solution to the bounded buffer producer/consumer problem by using general semaphores $S, F,$ and $E$. The semaphore $S$ is the mutual exclusion semaphore initialized to $1$. The semaphore $F$ corresponds to the number of free slots in the buffer and is initialized to $N$. The ... $(F)$ in the Consumer process (I) only (II) only Neither (I) nor (II) Both (I) and (II)
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Consider the following program segment. Here $\text{R1, R2}$ and $\text{R3}$ ... Assume that the memory is word addressable. After the execution of this program, the content of memory location $2010$ is: $100$ $101$ $102$ $110$
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what is the meaning of following query: select R.* from R,S where R.a = S.a and is unique R;
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The two numbers given below are multiplied using the Booth's algorithm. Multiplicand : $0101$ $1010$ $1110$ $1110$ Multiplier: $0111$ $0111$ $1011$ $1101$ How many additions/Subtractions are required for the multiplication of the above two numbers? $6$ $8$ $10$ $12$
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Consider the relation enrolled (student, course) in which (student, course) is the primary key, and the relation paid (student, amount) where student is the primary key. Assume no null values and no foreign keys or integrity constraints. Assume that amounts 6000, 7000, 8000 ... , Plan 1 executes faster than Plan 2 for all databases For x = 9000, Plan I executes slower than Plan 2 for all databases
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Consider the relation enrolled (student, course) in which (student, course) is the primary key, and the relation paid (student, amount) where student is the primary key. Assume no null values and no foreign keys or integrity constraints. Given the ... for which Query3 returns strictly fewer rows than Query2 There exist databases for which Query4 will encounter an integrity violation at runtime
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Exponentiation is a heavily used operation in public key cryptography. Which of the following options is the tightest upper bound on the number of multiplications required to compute $b^n \bmod{m}, 0 \leq b, n \leq m$ ? $O(\log n)$ $O(\sqrt n)$ $O\Biggl (\frac{n}{\log n} \Biggr )$ $O(n)$
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CS4820 Spring 2013 Notes on Turing Machines 19/26 (e) ever moves its head more than 481 tape cells away from the left endmarker on input ε ? (f) accepts the null string ε ? (g) accepts any string at all?(h) accepts every string?(i) accepts a ﬁnite set?(j) accepts a recursive set? (k) is equivalent to a Turing machine with a shorter description???
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Consider the following two transactions : T1 and T2. T1 : read (A); T2 : read (B); read (B); read (A); if A = 0 then B ← B + 1; if B ≠ 0 then A ← A - 1; write (B); write (A); Which of the following schemes, using shared and exclusive locks, satisfy the requirements for strict two ... B ← B + 1; then A ← A - 1; write (B); write (A); unlock (A); unlock (A); unlock (B); unlock (B); commit; commit;
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Let $G$ be the non-planar graph with the minimum possible number of edges. Then $G$ has 9 edges and 5 vertices 9 edges and 6 vertices 10 edges and 5 vertices 10 edges and 6 vertices
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A bag contains $10$ white balls and $15$ black balls. Two balls are drawn in succession. The probability that one of them is black and the other is white is: $\frac{2}{3}$ $\frac{4}{5}$ $\frac{1}{2}$ $\frac{1}{3}$
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Which one of the following in-place sorting algorithms needs the minimum number of swaps? Insertion Sort Quick Sort Heap Sort Selection Sort
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T(n) = T$(\frac{n}{3})$ + T$(\frac{2n}{3})$ + O(n)
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Complexity of Kruskal’s algorithm for finding the minimum spanning tree of an undirected graph containing $n$ vertices and $m$ edges if the edges are sorted is _______
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Consider the following $C$ function definition int Trial (int a, int b, int c) { if ((a>=b) && (c<b)) return b; else if (a>=b) return Trial(a, c, b); else return Trial(b, a, c); } The functional Trial: Finds the maximum of $a$, $b$, and $c$ Finds the minimum of $a$, $b$, and $c$ Finds the middle number of $a$, $b$, $c$ None of the above
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Let $L_1$ be the set of all languages accepted by a PDA by final state and $L_2$ the set of all languages accepted by empty stack. Which of the following is true? $L_1 = L_2$ $L_1 \supset L_2$ $L_1 \subset L_2$ None
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How many 32K $\times$ 1 RAM chips are needed to provide a memory capacity of 256K-bytes? 8 32 64 128
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Consider the grammar given below: $S \rightarrow x \ B \mid y \ A$ $A \rightarrow x \mid x \ S \mid y \ A \ A$ $B \rightarrow y \mid y \ S \mid x \ B \ B$ Consider the following strings. $xxyyx$ $xxyyxy$ $xyxy$ $yxxy$ $yxx$ $xyx$ Which of the above strings are generated by the grammar ? i, ii and iii ii, v and vi ii, iii and iv i, iii and iv
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Let $f(x)$ be the continuous probability density function of a random variable $x$, the probability that $a < x \leq b$, is : $f(b-a)$ $f(b) - f(a)$ $\int\limits_a^b f(x) dx$ $\int\limits_a^b xf (x)dx$
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Define languages $L_0$ and $L_1$ as follows : $L_0 = \{\langle M, w, 0 \rangle \mid M \text{ halts on }w\}$ $L_1 = \{\langle M, w, 1 \rangle \mid M \text{ does not halts on }w\}$ Here $\langle M, w, i \rangle$ is a triplet, whose first component $M$ ... but $L'$ is not $L'$ is recursively enumerable, but $L$ is not Both $L$ and $L'$ are recursive Neither $L$ nor $L'$ is recursively enumerable
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Let S be the binary semaphore variable S = 0 initially. Assume that no blocked processes exist in the system. The following signal (V), wait (P) operations are performed. The number of blocked processes at the end are _________. 4 P, 6 V, 9 P, 13 V, 14 P Answer given is 13 How? I am getting 8.
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Reply with solution as soon as possible...
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Consider the field $C$ of complex numbers with addition and multiplication. Which of the following form(s) a subfield of $C$ with addition and multiplication? S1: the set of real numbers S2: $\{(a + ib) \mid a$ and $b$ are rational numbers$\}$ S3: $\{a + ib \mid (a^2 + b^2) \leq 1\}$ S4: $\{ia \mid a \text{ is real}\}$ only S1 S1 and S3 S2 and S3 S1 and S2
Which one of the following options is CORRECT given three positive integers $x, y$ and $z$, and a predicate $P\left(x\right) = \neg \left(x=1\right)\wedge \forall y \left(\exists z\left(x=y*z\right) \Rightarrow \left(y=x\right) \vee \left(y=1\right) \right)$ ... $x$ $P(x)$ being true means that $x$ has exactly two factors other than $1$ and $x$
A function $f: \Bbb{N^+} \rightarrow \Bbb{N^+}$ , defined on the set of positive integers $\Bbb{N^+}$,satisfies the following properties: $f(n)=f(n/2)$ if $n$ is even $f(n)=f(n+5)$ if $n$ is odd Let $R=\{ i \mid \exists{j} : f(j)=i \}$ be the set of distinct values that $f$ takes. The maximum possible size of $R$ is ___________.
For the $IEEE$ $802.11$ MAC protocol for wireless communication, which of the following statements is/are TRUE? At least three non-overlapping channels are available for transmissions. The RTS-CTS mechanism is used for collision detection. Unicast frames are ACKed. All I, II, and III I and III only II and III only II only
A file system uses an in-memory cache to cache disk blocks. The miss rate of the cache is shown in the figure. The latency to read a block from the cache is $1$ ms and to read a block from the disk is $10$ ms. Assume that the cost of checking whether a ... sizes are in multiples of $10$ MB. The smallest cache size required to ensure an average read latency of less than $6$ ms is _________ MB.