Computer Science Previous Year Questions (page 42)

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A Wi-Fi router is fixed in place but connects devices wirelessly, so it is a fixed and wireless device. A laptop is mobile, and a desktop is fixed and wired.

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A capitalist (free-market) economy depends on market forces with little or no government intervention. A socialist economy is controlled by the state.

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In a bus topology all stations connect to one common cable called the backbone.

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The routing algorithm in the network layer decides which output line an incoming packet goes to and maintains the routing tables.

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Strategic information supports long-term policy decisions about business objectives and how well they are being met. It is used by top management.

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A DRAM cell stores each bit as charge on a tiny capacitor (with one transistor), which must be refreshed regularly. SRAM uses flip-flops.

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Inline functions put the function body at the call site, which removes call overhead. This is useful mainly for small, frequently called functions.

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A tangent is perpendicular to the radius at the point of contact, so AO = √(40² + 150²) = √24100 ≈ 155.2 mm.

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The photoelectric effect is the emission of electrons from a metal surface when light of short enough wavelength (high enough frequency) falls on it.

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Definiteness means every step of an algorithm is precisely and unambiguously defined.

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byte is one of Java's eight primitive types (byte, short, int, long, float, double, char, boolean). Arrays, String and classes are reference types.

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In doc* the * matches any characters, so rm doc* deletes all files whose names begin with 'doc'.

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The Tabular Data Control (TDC) is a Microsoft ActiveX control that reads a delimited data file and shows the data in chosen areas of a web page.

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In the ER model a relationship is an association among several entities, e.g. a student 'enrols in' a course.

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A group of RadioButtons lets the user choose exactly one option from several choices.

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The Insert key toggles between insert mode (text is inserted) and overwrite mode (typed characters replace existing ones).

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MIS components are people, hardware, software, data and procedures. 'Education procedures' is not a component.

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A variable is a symbolic name for a memory location whose value can change while the program runs.

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Inferential statistics uses sample data to make predictions or generalisations about a population. Descriptive statistics only summarises data.

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An angle measures the amount of rotation between two lines that meet at a point.

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A constructor in C# has no return type, not even void, so A is false. It has the class name and is called when an object is created.

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C's storage classes are auto, register, static and extern. 'Intern' is not a storage class.

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A peer-to-peer network has no dedicated server; all computers have equal status. So the statement that it has a dedicated server is false.

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Neither statement is true. In a queue, insertion (enqueue) happens at the rear and deletion (dequeue) at the front.

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10 = 1010₂, and 0.25 × 2 = 0.5 → 0, 0.5 × 2 = 1.0 → 1, so 0.25 = .01₂. Hence 10.25 = 1010.01₂.

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CGS unit of heat is the calorie, FPS uses the BTU, and SI uses the joule: (a)-(iii), (b)-(i), (c)-(ii). '(in)' in option A is a misprint of (iii).

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Triple DES uses three 56-bit DES keys, so the full key length is 3 × 56 = 168 bits.

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Optimisation problems ask for the best solution from a set of feasible solutions. Decision problems only need a yes/no answer.

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UDP (User Datagram Protocol, shown as 'Unit Datagram Protocol') lets applications send encapsulated IP datagrams without setting up a connection. TCP is connection-oriented.

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In e-commerce models such as B2B and B2C, 'B' stands for business organisations such as producers, manufacturers and sellers. 'C' is consumers and 'G' is government.

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Trade is the basic business activity of buying and selling goods and services.

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A Management Information System is a planned system for collecting, storing and sharing information that managers need to do their work.

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The Law of Diminishing Marginal Utility says each extra unit of a commodity gives the consumer less additional satisfaction.

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In a client/server network the central computer is the server and the other computers that request services from it are the clients.

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The class-loader hierarchy is Bootstrap (Primordial) → Extension → System (Application). The System ClassLoader is at the bottom, so by default it has no child class loaders.

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In-house development uses the organisation's own staff, infrastructure and knowledge, so it avoids vendor licences and outsourcing fees. That is why it is described as the lowest-cost route to a KM system.

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An information system is a set of interrelated components (people, hardware, software, data, procedures) that collect, process, store and distribute information to support decision-making and control.

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Translating source code into machine code is the job of a compiler or interpreter. The OS provides program execution, resource management and inter-process communication.

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ASP.NET server controls must carry runat="server", for example <asp:Button ID="b1" runat="server" />. Without it they are not processed on the server.

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Computer architecture includes Instruction Set Architecture, Microarchitecture and system designs such as Harvard and von Neumann. Software architecture is a software-engineering concept, not a computer architecture type.

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255.255.240.0 is a /20 mask, which leaves 12 host bits. 2¹² − 2 = 4094 usable hosts (the network and broadcast addresses are excluded).

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A virtual-circuit network sets up a path (connection) before data is sent. A datagram network routes each packet independently, with no setup.

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The standard risk responses are avoidance, transfer, mitigation and acceptance. Risk generation is not a risk management method.

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111111₂ = 32 + 16 + 8 + 4 + 2 + 1 = 63 (that is, 2⁶ − 1).

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Removing vertex 2 splits {1, 3, 4, 9, 10} from {5, 6, 7, 8}, removing 3 cuts off 9 and 10, and removing 5 cuts off 6. Vertices 1, 4, 7 and 8 lie on cycles, so the articulation points are 2, 3 and 5.

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A Decision Support System is an interactive computer-based system that analyses data and models to help managers make better decisions.

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MSIL (Microsoft Intermediate Language, also called CIL) is CPU-independent code produced by .NET compilers. The JIT compiler converts it to native code at run time.

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CMM is the Capability Maturity Model from the SEI. It rates software process maturity on five levels: Initial, Repeatable, Defined, Managed and Optimizing.

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Marginal revenue = change in total revenue ÷ change in quantity sold, that is, the extra revenue from one more unit.

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Burst time is the CPU time a process needs to complete its execution, not the time it takes to start. The other definitions are correct.