DSSSB TGT Computer Science Practice Set 5

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.

Explanation

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.

Explanation

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.

Explanation

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).

Explanation

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.

Explanation

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.

Explanation

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.

Explanation

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.

Explanation

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.

Explanation

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

Explanation

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

Explanation

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.

Explanation

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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The least significant bit has no incoming carry, so a half adder is enough there. The other three bit positions must add a carry, so they need full adders: 1 half adder and 3 full adders.

Explanation

10Base5 is the original Ethernet on thick coaxial cable (10 Mbps, 500 m segments), known as Thick Ethernet or Thicknet. 10Base2 is Thin Ethernet.

Explanation

Cache memory is a small, very fast memory between the CPU and main memory. It keeps frequently used data close to the processor, which cuts access time.

Explanation

The false statement is D: nulls do not reduce storage. They mark missing values and often still take up space. Too many joins, foreign keys as referential integrity, and primary keys as unique identifiers are all correct.

Explanation

The accumulator is the register that holds the result of arithmetic and logic operations in the ALU.

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14 units ÷ 2 per quantum = 7 time slices. The job is preempted at the end of each of the first 6 slices, so there are 6 context switches.

Explanation

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

Explanation

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.

Explanation

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

Explanation

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.

Explanation

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.

Explanation

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).

Explanation

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.

Explanation

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

Explanation

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

Explanation

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

Explanation

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

Explanation

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.

Explanation

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

Explanation

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

Explanation

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.

Explanation

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

Explanation

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

Explanation

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).

Explanation

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.

Explanation

An exception is an abnormal condition raised while a program is running, such as division by zero. Syntax errors are found at compile time.

Explanation

After pushing P to T, popping four times sends T, S, R, Q to the queue, leaving P on the stack. Dequeuing two gives T and S, which are pushed back (stack P, T, S). The next pop returns S.

Explanation

IEEE 754 single precision uses 1 sign bit, 8 exponent bits and 23 mantissa bits, 32 bits in total.

Explanation

In handshaking, the sender signals that data is ready and the receiver replies with an acknowledgement signal. Strobe control uses only one control signal.

Explanation

In Java, length is a field of an array, not a method, so X.length() will not compile and must be X.length. The <= would only cause a runtime exception, not a compile error.

Explanation

Swapping moves a whole process from main memory to disk (and back later) to free memory for other processes.

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CALL pushes the return address (the address of the next instruction) onto the stack, and RET pops it back into the program counter.

Explanation

GIF is a compressed image format that browsers support directly, so it suits graphics embedded in web pages. BMP and TIFF files are large, and HTML is not a graphics format.

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Classic ASP uses VBScript, where variables are declared with Dim, e.g. Dim name.

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read() reads bytes from a file opened in binary mode ('rb'). input() reads from the keyboard.

Explanation

Linux is a free, open-source operating system (kernel) released under the GNU GPL.

Explanation

The clauses must come in the order WHERE, GROUP BY, HAVING, ORDER BY. Conditions on groups such as COUNT(*) > 0 go in HAVING, not WHERE.

Explanation

LIKE with the wildcard _ matches exactly one character, so 'A____' matches names that start with A and have five characters. The = operator does not treat wildcards specially.

Explanation

Internship through school attachment puts student-teachers into real classrooms, so it offers the most scope for experiential (learning by doing) learning.

Explanation

Under NEP 2020, ABC stands for Academic Bank of Credit, a digital store of the credits a student earns so they can be transferred and counted toward a degree.

Explanation

An XML document has exactly one root element, which encloses every other element.

Explanation

A valid XML document must be well-formed and must also follow the rules of its DTD (or schema), so both statements are true.

Explanation

An absolute path name starts at the root directory and lists every directory down to the file. A relative path starts from the current directory.

Explanation

S points to "MySQL". S += 2 moves it past 'M' and 'y' to 'S', so cout prints the string from there: SQL.

Explanation

Corrected: the book's key says (b). U takes the values 70, 35 and 0 (all >= 0), so the loop body runs 3 times.

Explanation

The first 10 multiples of 5 are 5 to 50. Flowchart A starts at I = 5, adds I to S and then increases I by 5 while I ≤ 50. B increases I before adding, so it sums 10 to 55.

Explanation

In HTML, HEIGHT, WIDTH and BORDER values are in pixels, so the image appears 100 px high and 40 px wide with a 10 px border.

Explanation

The outer FRAMESET ROWS="25%,75%" makes two rows: Frame A in the first row, and a nested FRAMESET COLS="50%,50%" holding Frames B and C in the second. Options C and D swap FRAME and FRAMESET.

Explanation

Function 3, FUN(FUN &F), is the copy constructor, which runs when a new object is made from an existing one, as in FUN F2(F1). (FUN F2 = F1; also calls it, but C is the direct form.)

Explanation

A destructor has the class name with a tilde and no arguments, so ~FUN() (Function 5) is the destructor.

Explanation

First analyse the problem, then develop an algorithm, code it, and finally test and debug it: (C), (A), (B), (D).

Explanation

">" is a relational (comparison) operator. +, * and − are arithmetic operators.

Explanation

Going up the hierarchy, size grows and speed falls: registers, then cache, then main memory, then solid-state disk.

Explanation

In cycle stealing, the DMA controller takes the system bus from the CPU for a memory cycle at a time, so it steals cycles from the CPU.

Explanation

A mainframe is a large, powerful computer below a supercomputer that supports large databases and extensive I/O, and is used in central data processing.

Explanation

Closing balance = opening + receipts − payments = 2,50,000 + 1,75,000 − 1,25,000 = ₹3,00,000.

Explanation

Closing cash = 9,00,000 + 4,50,000 − 3,75,000 = ₹9,75,000.

Explanation

The skills of a second language develop in a natural sequence (listening, speaking, reading, writing), but they should be taught together in an integrated way rather than in isolation.

Explanation

A child picks up the mother tongue informally, by hearing and using it every day at home, without formal teaching of rules.

Explanation

Language is acquired in the natural order: listening first, then speaking, then reading, and finally writing (LSRW).

Explanation

Studying the material before class and using class time for assignments with the teacher is the flipped-classroom model, a form of blended learning that mixes self-study with face-to-face teaching.

Explanation

Google Drive stores files on remote internet servers and shares them by link, which is cloud computing.

Explanation

The holophrastic stage (about 12-18 months) is the one-word stage, when a single word expresses a whole sentence or idea.

Explanation

According to the source, a child's speech becomes fully fluent and free of errors only after the age of about 12 years.

Explanation

Acquisition is the subconscious way a language is picked up through exposure and use. Learning is the conscious study of rules.

Explanation

ICT changes and modernises teaching, so "promotes traditional education" is not one of its advantages. Bridging communication gaps, saving time and giving access to more information are advantages.

Explanation

Unit tests and class tests happen during teaching to check progress and give feedback, so they are formative assessment. Summative assessment comes at the end of a term.