Computer Science Previous Year Questions (page 15)

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Both cause differences. Cheques deposited but not yet collected appear in the cash book but not in the passbook. Interest or dividends collected by the bank appear in the passbook first.

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Both statements have the measures swapped. Lines of code, execution speed and memory size are direct measures. Functionality, quality and efficiency are indirect measures. So neither statement is correct.

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The SRS describes what the system must do, not how it is built internally. It treats the system as a black box, so it is called a black-box specification.

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Reverse engineering analyses existing code to recover its design and requirements specification. It is often used when maintaining legacy software.

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The spiral model is called a meta model because it includes the other models: each loop can use waterfall, prototyping or incremental steps, with risk analysis added.

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In the brute force debugging method, the program is filled with print statements and memory dumps in the hope that the printed values will reveal the faulty statement. It is the most common but least efficient method.

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Java's relational operators are <, >, <=, >=, == and !=. "=>" is not a valid operator in Java.

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Linux is a classic monolithic kernel. The Windows NT kernel also runs most OS services in kernel mode and is usually described as hybrid, but the exam treats both as monolithic.

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Threads give concurrency inside a single process. A process gives protection: each process has its own address space and resources. Both statements are true.

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A thread belongs to its process and shares only that process's resources, so it is private to the process. Threads of one process are not visible to other processes, so statement I is false.

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The standard process states are new, ready, running, waiting (blocked) and terminated. "Excite" is not a process state.

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C-SCAN is a disk scheduling algorithm. FCFS, SJF and SJN (shortest job next) are CPU scheduling algorithms.

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SRTF keeps choosing short jobs, so long jobs can starve. Round Robin gives every process a time slice quickly, so its response time is better than FCFS. Both statements are true.

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Because of the law of variable proportions, short-run marginal cost first falls and then rises, so the SMC curve is U-shaped.

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Repo rate, reverse repo rate and bank rate are all quantitative instruments that the RBI uses to control money supply and credit.

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In monopolistic competition, products are differentiated, so each firm faces a downward-sloping demand curve. A horizontal demand curve belongs to perfect competition.

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A LAN covers a limited area and is faster than a WAN. Communication through satellites and microwave links is a feature of a WAN, so only II and III are true.

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A WAN covers a wide geographical area and often uses satellites and microwave links. It is slower than a LAN, not faster, so statement III is false.

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ICMP stands for Internet Control Message Protocol. It carries error and control messages for IP, and ping and traceroute use it.

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Statement I is true: if the central hub fails, the whole star network goes down. Statement II is false: each node has its own link to the hub, so adding computers does not noticeably increase communication time.

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Manchester encoding has a transition in the middle of every bit, so each bit becomes two half-bit pulses. The pulse width is half that of straight binary, which doubles the baud rate.

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Circuit switching sets up a dedicated path between sender and receiver for the whole session, as in a telephone call. Packet and message switching share links.

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In VB.NET, Append is used as a symbolic constant (OpenMode.Append) in the FileOpen function, to open a file and add data at its end.

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Transplanted real-world models are offline business models moved to the internet, such as mail-order, advertising, subscription and free trial. Freeware, access provision and digital products are native internet models.

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Online trading involves all three steps: open a demat and online trading account, move funds from the bank account to the trading account, and place the confirmed order on the stock exchange through the online system.

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An AVL tree allows each node a balance factor (left height minus right height) of only −1, 0 or +1. So 1 is valid, while 2, 3 and 4 would need a rebalancing rotation.

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A pendant vertex has degree exactly one. An isolated vertex has degree zero.

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The matrix is square, vertex by vertex, and entry (i, j) = 1 exactly when vi and vj are joined by an edge. For example, V1 is joined to V3 and V4. So it is the adjacency matrix. An incidence matrix would be vertex by edge.

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Path costs: V1→V2→V3→V5 = 130, V1→V4→V3→V5 = 120, V1→V4→V5 = 130 and V1→V5 = 120. The minimum is 120.

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A DSS has a user interface for interacting with the user, plus a database and a model base or knowledge engine that does the analysis. Both are components.

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CDMA was first used commercially in cdmaOne (IS-95), a 2G digital cellular standard. Later CDMA-based 3G systems were CDMA2000 and WCDMA.

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The data speeds rise in this order: GSM (about 9.6-14.4 kbps), GPRS (about 114 kbps), EDGE (about 384 kbps), then LTE (tens to hundreds of Mbps).

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A circle is symmetric in all eight octants, so computing one point (x, y) gives eight points (±x, ±y) and (±y, ±x). Bresenham's and the midpoint algorithms use this.

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The rotation matrix is [cosθ −sinθ; sinθ cosθ]. With cos30° = √3/2 and sin30° = 1/2, this gives [√3/2 −1/2; 1/2 √3/2].

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HSL stands for Hue, Saturation and Lightness, for example hsl(120, 100%, 50%). Hue is an angle from 0 to 360°, and saturation and lightness are percentages.

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JPEG stands for Joint Photographic Experts Group, the committee that created this lossy image compression standard.

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In a sequence structure, statements run one after another in the written order. Each runs exactly once and none repeats. They are not executed in any order, so III is false.

Explanation

Sorted, the data is 9,15,16,20,23,26,28,32,33,34,35,43, so P = (26+28)/2 = 27. After the replacements it is 9,15,20,26,28,30,32,32,33,34,35,43, so Q = (30+32)/2 = 31. Then 3P − 2Q = 81 − 62 = 19.

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By Bayes' theorem, P(M | red) = (½ × 5/9) / (½ × 3/5 + ½ × 5/9) = (5/9) / (52/45) = 25/52.

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With two points, Lagrange's formula gives f(x) = 3(x−4)/(2−4) + 5(x−2)/(4−2) = −1.5x + 6 + 2.5x − 5 = x + 1. Check: f(2) = 3 and f(4) = 5.

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Effective teaching lets students learn from peers and encourages them to think independently and build their own knowledge, as constructivism suggests. Both are characteristics.

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Activity materials should be relevant, contextual and linked to real life. The textbook is still an essential basic resource for teaching and learning. Both statements are accepted as correct.

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Formative assessment is continuous and built into everyday teaching. It is diagnostic and remedial, involves students and gives feedback. Holding it at fixed intervals is more typical of periodic or summative assessment.

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Statement I describes assessment of learning (summative), which measures achievement after teaching. Statement II describes assessment for learning (formative), which uses results during teaching to improve learning. Both are correct.

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Acquisition happens naturally through use in real communicative settings, like a home language. Learning happens through explicit classroom teaching of rules and vocabulary. Both definitions are correct.

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Art education covers both visual or tangible arts, such as drawing, painting and sculpture, and performing arts, such as music, dance and drama.