Computer Science Previous Year Questions (page 36)

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Calling form.submit() on a form element submits it from JavaScript. send(), submitForm() and post() are not form methods.

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JavaScript arrays are dynamic objects. One array can hold numbers, strings, objects and other types together, and it can grow, shrink or be changed after it is created.

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Authoring software (such as Adobe Animate or Director) is used to combine text, images, audio and video into interactive multimedia presentations. Media players only play the files.

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The ?: operator is right-associative, so the expression is x ? y : (a ? b : c). x = 0 picks the second part, and a = 0 then picks c.

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Erasing an EPROM with UV light sets every bit to 1 (all cells read FF). Programming then writes 0s where they are needed.

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2A = [2 8; 6 10] and 3B = [9 6; 6 3], so 2A − 3B = [2−9 8−6; 6−6 10−3] = [−7 2; 0 7].

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A Hermitian matrix equals its conjugate transpose, so aᵢⱼ = conj(aⱼᵢ). aᵢⱼ = aⱼᵢ is the rule for a symmetric matrix, and the minus forms are for skew types.

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Mobile phones and TV broadcasting send signals on radio waves and microwaves, the long-wavelength part of the spectrum, because these travel far and pass through the atmosphere.

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EEPROM (Electrically Erasable Programmable ROM) can be written and erased with electrical signals. EPROM needs UV light to erase, and mask ROM is fixed at manufacture.

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A switch statement chooses one of many case labels by the value of a single expression. Loops repeat code and goto jumps; they do not choose among several cases.

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A business plan sets out the new business's goals, strategy, target market, operations and financial projections. MoA, AoA and the Certificate of Incorporation are legal company documents.

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When fast electrons hit a metal target (an X-ray tube), X-rays are produced. Their wavelengths range from about 1 nm down to 10⁻³ nm.

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An output unit takes the binary results from the CPU and converts them into a form people can understand, such as text on a screen, print or sound.

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An if statement checks a condition and runs its block only when the condition is true, so it is used for decision making.

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Option D is incorrect: a singly linked list has no index arithmetic, so you must walk from the head node by node to reach an element. It has sequential access, not random access.

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Try y = x² + bx + c. Then y'' + 2y' + y = x² + (4 + b)x + (2 + 2b + c). Matching with x² + 2x gives b = −2 and c = 2, so the particular integral is x² − 2x + 2.

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The dual aspect concept says every transaction has two equal effects, a debit and a credit, which is the basis of the equation Assets = Liabilities + Capital.

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The provision is 5% of debtors, so opening debtors are 2,50,000/0.05 = 50,00,000 and closing debtors are 60,00,000. Credit sales = closing + collections − opening = 60L + 75L − 50L = ₹85,00,000.

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CALL pushes the return address onto the stack. The stack grows downward, so SP is decreased by 2 (or by 4 on 32-bit systems) before the address is stored.

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From the mean position, x = A sin(2πt/T). With T = 16 and t = 4, sin(π/2) = 1, so the particle is at an extreme and A = 10 cm.

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A do-while loop runs its body first and then tests the condition, so Q is true and P is false. R is false because the body can be a block in braces.

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In bank reconciliation you find bank-statement items that need entries in the cash book, list cash-book entries not yet in the bank statement, and correct clerical errors. All three steps are part of the process.

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A linked list must be traversed node by node from the head. In the worst case the key is the last node or is missing, which needs n comparisons, so the time is O(n).

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Row 1 × columns: 1−1+4 = 4, 2+0+6 = 8, 1+3+2 = 6. Row 2: 3, 8, 9. Row 3: 2−3+6 = 5, 4+0+9 = 13, 2+9+3 = 14. This matches option B.

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The debt-to-equity ratio compares borrowed funds with owners' funds. A high ratio means heavy borrowing, with more fixed interest burden and higher financial risk.

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P(A) = p(2) + p(3) = 2/10 + 3/10 = 5/10 = 1/2.

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The median depends only on the middle position of the ordered data, so very large or very small values do not change it. The mean and range are directly affected.

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The memory unit (main memory) holds the program instructions and data while they are being executed. The CPU fetches them from there.

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A live chat delivers messages instantly while both people are online, which is real-time (synchronous) communication. Blogs, emails and comments are asynchronous.

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EVA = NOPAT − (capital employed × cost of capital). It measures the value a company creates above the cost of the capital it uses.

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The operating system schedules processes. It decides which program runs on the CPU, when, and in what order.

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XMPP (Jabber) is an open XML-based protocol for instant messaging, presence (online status) and contact lists (rosters). IMAP is for email, and SIP sets up calls.

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Good netiquette means checking that a post is respectful, relevant to the thread and follows the forum rules.

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The CPU contains registers, the control unit and the ALU. RAM is main memory, which sits outside the CPU and is reached over the bus.

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Diagnostic assessment is used to find the specific causes of a learner's persistent difficulties, so that remedial teaching can be planned.

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Scientific ways of gaining knowledge rely on sensory observation, action (experiment) and reasoning. Reading fiction is not a systematic method of verifying knowledge.

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Pedagogical analysis breaks a subject's content into units and plans the objectives, teaching activities and evaluation for each one.

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Growth is a quantitative change (size, height, weight) that is neutral in value. Development is a qualitative, progressive change toward maturity and is seen as positive in value.

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Learning disabilities are identified with special assessments carried out by trained professionals such as special educators, who then plan interventions.

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Art education gives children a creative way to express feelings and emotions, and it builds aesthetic sense.

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Learning resources should be chosen by fit with learning outcomes, cost and access, and cultural relevance. Popularity on social media matters least.

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A technique is a specific classroom activity or device used within a method, for example a mnemonic, questioning or role play.

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Gender socialisation teaches children both that boys and girls are different and that one is ranked above the other (difference and hierarchy).

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Using language actively in every subject (discussion, explanation, questioning) builds listening and speaking comprehension in context.

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Semaphores (with a fair, e.g. FIFO, waiting queue) let processes wait in order to enter the critical section, so no process waits indefinitely. Interrupts, paging and context switching are not synchronisation tools.

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Standard SQL supports -- for single-line (and end-of-line) comments and /* ... */ for block comments. // is a comment in C++/Java/JavaScript, not in SQL-99.

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Standard SQL requires the keyword INTO in an INSERT statement: INSERT INTO table VALUES (...). Omitting INTO is only accepted by some vendors such as MySQL or SQL Server, so D is invalid in standard SQL.

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TLS (successor of SSL) encrypts data between browser and server and is the security layer of HTTPS. Plain HTTP, ARP and FTP do not provide privacy.

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CloseHandle releases the kernel object and the resources tied to the handle. If it is never called, those handles and resources stay allocated (a handle/resource leak) until the process ends.

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The sender signs a hash (message digest) of the message. The receiver recomputes the hash and compares it; any change to the message gives a different hash, so the hash value guarantees integrity.