Computer Science Previous Year Questions

Explanation

The TYPE attribute of <OL> sets the numbering style; TYPE="A" gives upper-case letters (A, B, C...). START only sets the starting value, and VALUE belongs to <LI>.

Explanation

Records are stored one after another, so the Nth record begins after N−1 records, at byte offset (N−1)*sizeof(EMP). seekp() moves the put pointer there; tellg() only reports the current position.

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Corrected: the book's key says (a), but its own explanation says a column is a vertical subset of a table.

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ASCII codes of letters are consecutive: A=65, B=66, C=67, D=68, so E = 65 + 4 = 69.

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An IF block placed inside another IF block is a nested IF; the inner condition is checked only when the outer one is true.

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Contiguous allocation does suffer internal fragmentation, since a file's last block is usually only partly filled; its main problem is external fragmentation. The other three statements are correct.

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Corrected: the book's key says (c). A cycle in a resource-allocation graph does not always mean deadlock (with multiple instances), so A is false; B and C are correct.

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XML has no predefined tags, so the meaning and allowed structure of user-made tags must be described in a Document Type Definition (DTD) or schema.

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XML is a simplified subset of SGML (Standard Generalized Markup Language), the meta-language from which HTML was also derived.

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ORDER BY takes the column first and the direction after it, separated by commas: ORDER BY MARKS DESC, ROLLNO ASC sorts by marks high to low and breaks ties by roll number ascending. The other options have wrong syntax.

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Section-wise averages need GROUP BY SEC with SELECT SEC, AVG(MARKS); ORDER BY only sorts and does not form groups, and GROUP BY MARKS groups the wrong column. Option C is the intended query (the "*" is a printing slip).

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In-order (left, root, right) gives a+b*c, pre-order (root first) gives +a*bc, and post-order (root last) gives abc*+.

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The loop body runs once per iteration, so the loop's running time is at most the time of the statements inside it (including the test) multiplied by the number of iterations.

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3245 ÷ 16 = 202 remainder 13 (D); 202 ÷ 16 = 12 remainder 10 (A); 12 = C. Reading upward gives CAD.

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Replace each hex digit with 4 bits: 7 = 0111, A = 1010, 4 = 0100, giving 011110100100 = 11110100100.

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PCI (Peripheral Component Interconnect) is a high-bandwidth, processor-independent bus that can work as a mezzanine or peripheral bus.

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Sequential, direct, random and associative access are the access methods used to describe computer memory systems.

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256 colours need 8 bits = 1 byte per pixel. 640 × 480 = 307,200 bytes, and 307,200 ÷ 1024 = 300 KB.

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The figure shows a wave with amplitude, period, crest and trough plotted against time, which is how a sound wave is represented.

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Samples needed = sampling rate × time = 100,000 per second × 0.1 s = 10,000 samples, so the acquisition memory must hold at least 10K.

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The XML declaration in the prolog starts with <?xml, as in <?xml version="1.0"?>. Option A is the only one that uses the <? processing-instruction form.

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With multiple threads the browser can download and render several small images at the same time instead of one after another, which speeds up loading.

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Resolution = 1/(2⁸ − 1) = 1/255 ≈ 0.0039, which is about 0.39%.

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The log-scale graph shows transistors per chip doubling at regular intervals, which is Moore's law.

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Following Stallings' list of Intel processors, the Intel Core was the first x86 microprocessor with a dual core, meaning two processors on a single chip. Core 2 Duo came later.

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The program counter holds the address of the next instruction to be fetched and executed.

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Semaphores are a synchronization tool. They control how concurrent processes access shared resources, which solves process synchronization problems, including mutual exclusion.

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A control array is a group of controls of the same type that share one name and are told apart by an Index property.

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At most, the natural join can produce every combination, as when there are no common attributes or every row shares the same common value. That is 3 × 2 = 6 tuples.

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CELLPADDING sets the space between a cell's content and its border. CELLSPACING sets the space between neighbouring cells.

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The open-count records how many processes have the file open. open() increments it and close() decrements it, and the entry is removed when it reaches zero.

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Recursion uses a stack of activation records, scheduling uses a queue (first come, first served), and sorting can use a binary tree (as in a BST or heap).

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An outer join keeps the unmatched tuples, padded with NULLs, that a natural join would drop.

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Stacks are used for parenthesis balancing and infix-to-postfix conversion, so (A) and (C) are correct. Process scheduling uses queues, not stacks.

Explanation

In a multimode step-index fiber, the core has the same density (refractive index) everywhere, with a sudden step at the cladding. In graded-index fiber the density changes gradually.

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MPEG temporal compression removes redundant frames. Consecutive frames are largely the same, so only the differences from reference frames are stored.

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A Static variable keeps its value between procedure calls. It is not reinitialized each time the procedure runs.

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DES is a symmetric block cipher that encrypts data in 64-bit blocks with a 56-bit key.

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Plagiarism is presenting someone else's ideas or creations as your own. Piracy is unauthorized copying, and IPR is the legal protection itself.

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HTTP (HyperText Transfer Protocol) is used to access web pages on the World Wide Web. SMTP is for email, and SLIP is a serial-line link protocol.

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Web pages are written in HTML (HyperText Markup Language). HTTP is the protocol that transfers them.

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X + X'Y = (X + X')(X + Y) = 1·(X + Y) = X + Y, by the distributive law.

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32 MB = 32 × 2²⁰ bytes = 2⁵ × 2²⁰ = 2²⁵ bytes, so 25 address bits are needed.

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128 MB = 2²⁷ bytes. With 8 bytes (2³) per word that is 2²⁷/2³ = 2²⁴ words, so 24 bits are needed.

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Parallelism means tasks really run at the same time, which needs at least two processors.

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In inorder, preorder and postorder the left subtree is always visited before the right subtree. Only the position of the root changes.

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Each binary search step does a constant amount of work and continues in one half of the array, giving T(n) = T(n/2) + O(1), which solves to O(log n).

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In a BST, an inorder traversal (left, root, right) visits the keys in ascending order.

Explanation

Order C reproduces the table: 46→6, 34→4, 42→2, 23→3, 52→2 (taken) then 3, 4 (taken) so 5, and 33→3 then 4, 5, 6 (taken) so 7.

Explanation

Both statements are true as intended: in JavaScript a variable is created with the var keyword (the word is missing from the question), and JavaScript is loosely (dynamically) typed, so variables have no fixed type.