Computer Science Previous Year Questions (page 41)

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The management point of view of knowledge management focuses on determining, organising, directing, facilitating and monitoring knowledge practices to meet business goals.

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Recovery testing deliberately makes the software fail in different ways and checks that recovery is performed correctly.

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By default BASH shows $ as the prompt for a normal user; # is shown for the root user.

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Flash memory is non-volatile (NVRAM-type) memory that keeps its data without power, as in pen drives and SSDs. Cache, registers and main RAM are volatile.

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Quadratic equations are solved by factorisation, completing the square or the quadratic formula. Convergence is not a method for solving them.

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Microsoft developed the .NET Framework and released version 1.0 in 2002.

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Front-end development tools help developers build attractive website layouts and user interfaces quickly. Back-end tools deal with servers and databases.

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A cube of side x has volume x³ and six square faces, so its total surface area is 6x².

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In a DTD an element is declared as <!ELEMENT element-name category>. <!ATTLIST> declares attributes and <!ENTITY> declares entities.

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C is false: a monolithic kernel keeps user and kernel services in the same address space. A microkernel keeps them in separate address spaces.

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Sequential models such as the waterfall model are the oldest paradigms. They follow a linear flow, which often does not match changing real-world requirements.

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A leading 0 makes 017 an octal literal, which equals 15. The program prints 121 201 15, which is option (B) (its text shows a stray leading 1).

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Demand is perfectly elastic when a negligible change in price causes an infinite change in quantity demanded (a horizontal demand curve).

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A random-scan (vector) display moves the electron beam like a pencil, drawing only the lines of the picture. Raster scan sweeps the whole screen row by row.

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Range = largest − smallest = 101 − 6 = 95.

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A flowchart shows an algorithm graphically using standard symbols joined by arrows. Pseudocode is a text description.

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In a connectionless network service packets are called datagrams and the network a datagram network. Connection-oriented service uses a virtual-circuit network.

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JavaScript runs in the browser and is used to build the front end. PHP and Django are server-side, and SQL is for databases.

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IMAP servers listen on TCP port 143. Port 443 is HTTPS, 80 is HTTP and 20 is FTP data.

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Knowledge is the expertise and skills a person gains through experience or education, i.e. theoretical or practical understanding of a subject.

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Efficiency (ISO 9126) means the software makes optimal use of system resources, measured by time behaviour and resource behaviour.

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The Poisson distribution is discrete; it counts events in a fixed interval. Normal, log-normal and exponential distributions are continuous.

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In Mobile IP, the foreign agent is a router on the visited (foreign) network that serves the mobile node while it is attached there.

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chmod takes the permission changes (e.g. u+x or 755) and the file names to apply them to, as in chmod 755 file.txt.

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In a flowchart the rectangle is the process (processing) symbol. The diamond is a decision, the parallelogram is input/output and the oval is start/end.

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A Bezier curve is a spline defined by a set of control points, using polynomial (Bernstein) blending functions.

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Messages exchanged between transport entities in the transport layer are called segments (TPDUs). Packets belong to the network layer and frames to the data link layer.

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Microeconomics studies the behaviour of individual economic units such as a consumer, a household or a firm. Macroeconomics studies the economy as a whole.

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In Cohen-Sutherland clipping, a line that crosses (intersects) the window boundary is partially visible and must be clipped. Lines fully inside are accepted and lines fully outside are rejected.

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y points to x, so *y = 8. x * *y * x + *y = 8 × 8 × 8 + 8 = 512 + 8 = 520.

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A good OS should complete many jobs per unit time (high throughput) and finish each job quickly (low turnaround time).

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Knowledge refining adds value to collected knowledge by discovering relationships, abstracting and preparing it to be shared.

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A transposition cipher only rearranges the order of the letters and does not change them. A substitution cipher replaces letters, disguising them.

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In ASP.NET an event is an action or occurrence such as a click, key press, mouse movement or system notification that code can respond to.

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Interdependence means the parts of a business system are closely interacting and depend on each other.

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Interpolation is estimating y = f(x) for an x that lies between the given values x₀ and xₙ. Estimating outside this range is extrapolation.

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PHP is a server-side scripting language, so it is not a front-end tool. AngularJS, jQuery and Chrome DevTools are used for front-end work.

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The cycle is: transactions → journal → ledger → trial balance → adjustment entries → adjusted trial balance → closing entries → financial statements, as in (B).

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Parentheses ( ) (function call or grouping) have the highest precedence. * comes next, then !=, and ^ (bitwise XOR) is lower.

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The representational quality of information covers interpretability, ease of understanding, format and concise or consistent representation (coherence and compatibility).

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The DEFAULT constraint supplies a default value for a column when no value is given in an INSERT. NOT NULL, CHECK and UNIQUE do the other jobs.

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This is the AICPA definition of accounting, used for financial accounting: recording, classifying and summarising financial transactions in money terms and interpreting the results.

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A DOM parser loads the whole XML document into memory as a tree of objects. SAX is event-based and builds no tree.

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Packing, loading and shipping the goods to the buyer are part of the delivery/fulfilment step of the e-commerce process.

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NAND is NOT-AND, so its output is (xy)'. (x+y)' is NOR, x+y is OR and xy is AND.

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Sass (Syntactically Awesome Style Sheets) is one of the most widely used CSS extension (preprocessor) languages.

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Newton's divided difference formula works for unequally spaced xᵢ. Newton's forward/backward and Gauss formulas need equally spaced points.

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TDMA lets several users share one frequency channel by giving each user its own time slot.

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A counter stores, and may display, the number of times an event has occurred, usually counting clock pulses.

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A queue is FIFO (first in, first out), so the first element inserted is the first removed. A stack is LIFO.