Computer Science Previous Year Questions (page 48)

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An algorithmic solution follows well-defined, exact steps, so its correctness can be checked easily. A heuristic solution is only approximate.

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A Bezier curve is a parametric curve, with points given as functions of a parameter t from 0 to 1, defined by its endpoints and control points.

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Reading "S" as 8: the sum is 10 + 11 + 7 + 6 + 8 + 11 + 12 + 13 + 12 = 90, and 90 ÷ 9 = 10.

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16:9 (widescreen) is the standard aspect ratio for modern monitors and TVs, used for example by 1920 × 1080.

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Animation moves objects by applying geometric transformations frame by frame: translation, rotation and scaling, usually as matrix operations. Rasterisation and lighting models only affect how each frame is drawn.

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System design gives the most abstract view of the whole system. Architectural design breaks it into sub-systems and components, and detailed design specifies each module for implementation.

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Linear (sequential, waterfall) models assume requirements are fixed at the start and each phase is finished before the next. They cannot easily handle requirements that change during development, unlike evolutionary, incremental or agile models.

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(743)₈ = 111 100 011 in binary. The Gray code keeps the MSB and then XORs each pair of adjacent bits: 1, 0, 0, 0, 1, 0, 0, 1, 0, which gives 100010010.

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A compiler translates the whole high-level source program into object (target) code in one go. An interpreter executes line by line without producing object code, and an assembler translates only assembly language.

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In the subscription revenue model, customers pay a fixed recurring fee (monthly, quarterly or yearly) to access a service or content, as with Netflix or online magazines.

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RISC processors use a small set of simple, fixed-length instructions that need less complex decoding hardware, so they use less power. ARM chips in mobiles are an example. CISC needs more transistors and power.

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Retardation (wave) plates are made of birefringent crystals. Double refraction splits light into ordinary and extraordinary rays that travel at different speeds, and this produces the phase difference between them.

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Selection sort always scans the whole unsorted part to find the minimum, making about n(n−1)/2 comparisons whatever the input order. So both its best and worst cases are O(n²).

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Handover between two different kinds of network, such as a satellite network and a terrestrial cellular network, is called inter-system handover. Intra- and inter-satellite handovers happen within the satellite system.

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Piecewise constant (nearest-neighbour) interpolation simply gives each point the value of the nearest data point, so it is the simplest and least demanding interpolant. The key treats this as the softer method. In terms of smoothness, spline interpolation gives the smoothest curves.

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TCP (connection-oriented), UDP (connectionless) and SCTP (stream control) all work at the transport layer. FTP, DNS and Telnet are application-layer protocols, ICMP is network-layer, and ARP/RARP work between the network and link layers.

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The CO₂ laser emits at 10.6 µm from a transition between vibrational energy levels of the CO₂ molecule (asymmetric stretch to symmetric stretch mode).

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Functional activities directly produce the required features and are essential to complete the project's work tasks. Non-functional activities support quality aspects and are treated as not mandatory for completion.

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Sole proprietorship, owned and run by one person, is the most common business form because it is easy and cheap to set up and has few legal formalities.

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Only when a process moves from running to terminated (exit) does the OS reclaim all of its memory. In sleeping or ready states the process still exists and keeps its address space.

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DDL commands (CREATE, ALTER, DROP) define and change the structure (schema) of relations and remove them. DML only queries and modifies the data stored in them.

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Operations research applies mathematical methods such as linear programming, queuing theory and simulation to decision-making problems, so it is a branch of applied mathematics.

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An XML processor (parser) reads XML documents and gives applications access to their content and structure, for example through DOM or SAX. An XML schema only defines the valid structure.

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In Nonaka's SECI model, socialisation (sharing experiences such as observation, imitation and practice) creates tacit knowledge, which is personal know-how that is hard to write down.

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In a linear list, elements are arranged in a sequence where each has one successor. An array is the classic linear list. Trees and graphs are non-linear structures.

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Value is a qualitative measure (perceived worth or benefit) that depends on judgement, so it is hard to quantify precisely, unlike measurable items such as infrastructure.

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BTS means Base Transceiver Station: the cell-site equipment with radio transmitters and receivers that connects mobile phones to the cellular network.

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A final method cannot be overridden in a subclass, so (A) is false. The varargs main with modifiers in any order is valid, abstract classes cannot be instantiated, and Java 8 interfaces allow default methods.

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The ground state is the lowest, stable energy level. An atom stays there indefinitely unless it absorbs energy, so its lifetime is taken as infinite. Excited states last only about 10⁻⁸ s.

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Ext4 (fourth extended file system) has been the default file system in most Linux distributions since about 2008. It replaced Ext3 and supports larger files and volumes and journaling.

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Two 4-bit inputs give 2⁸ = 256 combinations. Only 10 × 10 = 100 are valid BCD digit pairs (0-9 each), so 256 − 100 = 156 combinations are invalid.

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The TCP/IP internet layer (IP) handles packets, also called datagrams. The transport layer uses segments, and the network access (link) layer uses frames.

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document.write sends text into HTML, where a newline character is displayed as a single space. The page therefore shows 'Hello India' on one line.

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A Visual Display Unit (monitor) shows output from the computer. Mouse, light pen and keyboard are input devices.

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In a relational database, data is stored in tables (relations) of rows and columns, and the tables are linked through keys. Fields and records are just parts of a table.

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The operating system is the program that acts as an interface between the user and the hardware, managing resources such as the CPU, memory and devices. The kernel is only its core part.

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In the opinion survey (collective opinion / sales-force composite) method of demand forecasting, salespeople estimate sales in their areas and these estimates are combined into a forecast.

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Armstrong's axioms are only reflexivity, augmentation and transitivity. Pseudo-transitivity is a derived rule (inferred from these axioms), not one of the axioms themselves.

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An organisation is defined as a formal social unit (a structured group of people) set up to achieve specific goals. Management and marketing are functions within it.

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The main purpose of interconnecting computer networks worldwide (the Internet) is communication, that is, exchanging messages between users and systems, for example by email and messaging.

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Commerce covers the buying and selling of goods and services, especially on a large scale, together with supporting activities such as transport, banking and insurance.

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Static memory (like SRAM) keeps its contents unchanged as long as power is on, without refreshing. Dynamic memory (DRAM) leaks charge and must be refreshed regularly.

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In Linux, system-wide configuration files (such as /etc/passwd, /etc/fstab and /etc/hosts) are kept in /etc. /dev holds device files, /bin holds essential binaries and /root is root's home directory.

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In Bayesian probability, probability is a degree of belief or view held about an event, and these beliefs must obey the rules of probability calculus, with updates made by Bayes' theorem.

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OLX is a consumer-to-consumer (C2C) marketplace where individuals sell used goods directly to other individuals, with the platform acting only as an intermediary.