Basic components of a computer system

The governing concept is specialised input: a device is specialised when it is designed to capture a particular form of information. A barcode scanner optically reads coded lines or patterns on products and converts them into digital data for the computer. Option A is correct. Printing is output, supplying power is an electrical function, and playing sound is audio output, so B, C, and D do not fit.

The governing concept is specialised output hardware. A plotter is designed to produce large, highly precise line drawings, such as maps, engineering plans, and architectural designs. Its controlled movement is useful when accuracy and size matter. Option B is correct. Sound production, typing, and networking are functions of other devices, so options A, C, and D do not describe a plotter’s main purpose.

The governing concept is the data-processing cycle. Data means raw facts, symbols or observations that may not yet have useful context. When a computer organizes, calculates or interprets those facts, the resulting meaningful output is information. Hence option A is correct. Data and information are not always identical, information is not hardware, and data can exist digitally rather than only on paper.

The governing concept is RAM as temporary working memory. When programs are active, they use RAM to hold instructions and data that the processor needs quickly. Increasing RAM can therefore reduce the need to move data to slower storage and can improve multitasking, such as using a browser, document editor and media player together. Option D is correct; RAM does not change paper size, weight or printer ink.

The governing concept is the integrated computer system. A complete system accepts input, processes it using the processor and memory, stores data or results, and produces output; software coordinates these activities. Therefore option A gives the most comprehensive description. A CPU is only one component, a monitor and keyboard are only two peripherals, and internet access is not required for every computer system.

The governing concept is the computer system’s central hardware interconnection. The motherboard is the main circuit board containing or connecting sockets, buses, memory interfaces, and expansion connections for major components such as the CPU and storage devices. Therefore, option D is correct. A hard disk stores data, a power supply provides electrical energy, and a speaker produces sound; none serves as the main connecting board.

The governing concept is the division of CPU responsibilities. The Arithmetic and Logic Unit, or ALU, performs arithmetic operations such as addition and subtraction and logical operations such as comparison, so option A is correct. The Control Unit directs instruction flow, while main memory and storage hold data or programs; they do not primarily perform the calculations described.

The governing concept is instruction control within the CPU. The Control Unit fetches and decodes instructions, then sends timing and control signals so the processor, memory, and input-output devices perform their tasks in the proper sequence. Thus option B is correct. Permanent file storage belongs to storage devices, printing belongs to an output device, and sound recording belongs to an input device.

The governing concept is temporary working memory. Random Access Memory holds the programs and data that the CPU is actively using, allowing rapid access during execution; therefore option C is correct. ROM contains fixed startup instructions, an optical disc is secondary storage, and printer memory is limited device-specific memory. RAM is volatile, so its active contents normally disappear when power is removed.

The governing concept is non-volatile memory, which retains information without continuous electrical power. Read Only Memory stores firmware or startup instructions needed when the computer begins to boot, so option D is correct. RAM and cache are generally volatile working memories, while virtual memory uses storage to extend RAM and is not the permanent home of startup firmware.

The governing concept is processor cooling. A heat sink is a metal component with fins that conducts heat away from the processor and spreads it over a larger surface area, where airflow can remove it; therefore option D is correct. A fan may move air across the sink, but the sound card, network card, and memory card perform audio, networking, and storage functions rather than heat removal.

The governing concept is network communication hardware. A network interface card, or NIC, provides the computer with a wired Ethernet or wireless connection and exchanges data frames with other devices on a network, so option A is correct. A sound card processes audio, a graphics card renders images, and a memory module temporarily holds data and instructions for active processing.

The graphics processing unit, or GPU, is designed to process and rapidly render visual data such as images, animations, and videos. It sends the prepared graphical output to the display. A power supply provides electrical power, a modem handles network communication, and a scanner captures physical documents, so none of those is the best answer.

A sound card, also called an audio adapter, processes audio signals received from devices such as microphones and sends output to speakers or headphones. A network card manages network communication, a motherboard battery preserves clock settings, and a storage controller manages drives. Therefore, the sound card is the correct internal component.

The CMOS battery supplies a small amount of power to the real-time clock and related firmware settings when the computer is switched off. If it becomes weak, the date and time may reset repeatedly. Main memory stores working data, a processor fan cools the processor, and a speaker produces sound, so CMOS battery is correct.

Ports are physical connection points through which external or peripheral devices communicate with a computer. A keyboard, mouse, printer, or display may connect through an appropriate port and cable. Pixels are tiny picture elements, folders organize files, and sectors are storage divisions. Thus, ports is the only option describing device connection points.

Universal Serial Bus, abbreviated as USB, is a widely used interface standard for connecting devices such as keyboards, mice, storage drives, cameras, and phones. VGA is mainly a video standard, ROM is a memory type, and the CPU performs processing rather than serving as a connection standard. Therefore, option B is correct.

High-Definition Multimedia Interface, commonly called HDMI, is a digital connector designed to carry both video and audio through one cable. This allows a monitor, television, or projector to receive picture and sound together. A mouse connector and keyboard connector serve input devices, while a power connector supplies electricity, so HDMI is correct.

A bus is an internal communication pathway made of lines or connections that carry data, addresses, and control signals among the processor, memory, and other components. A port is normally an external connection point, a folder organizes files, and a pixel is a picture element. Therefore, the internal data pathway is the bus.

The governing concept is the difference between primary memory and secondary storage. Random Access Memory, or RAM, is primary memory because the processor can access it directly while programs are running; it is generally volatile and loses its contents when power is removed. Thus option B is correct. Hard disks, optical discs, and external drives are secondary storage devices used for longer-term retention.

The governing concept is the memory hierarchy. Cache memory is placed close to the processor and stores frequently or immediately needed data, so it can be accessed faster than ordinary main memory. It has less capacity and is therefore generally smaller as well. Consequently, option D is correct. Cache is not paper-based or external, and it is not normally described as permanent storage.

The governing concept is the processor’s internal storage hierarchy. Registers are very small, extremely fast storage locations inside the CPU that hold operands, addresses, instructions, or intermediate results needed immediately during execution. Therefore option A is correct. Folders organise files, sectors are divisions of storage media, and ports are connection interfaces; none is a fast storage location inside the processor.

The governing concept is the role of main memory, or RAM, as temporary working space for active programs and data. When more RAM is available, the operating system can keep more applications and information ready for use, reducing the need to move data repeatedly to slower storage. This generally improves multitasking, although it does not guarantee faster printing, enlarge the monitor, or remove the need for electricity. Therefore, option B is correct.

The governing concept is hardware compatibility. A motherboard provides slots, sockets, buses, and electrical interfaces, so a replacement component must have a matching connector and supported technical standards. For example, a memory module or processor may fail to fit or operate if its type is unsupported, even when it is otherwise functional. Compatibility does not change screen appearance, printer ink use, or keyboard size. Therefore, option D is correct.

The governing concept is the memory hierarchy. Cache memory is a small, fast memory located very close to or inside the processor and holds frequently needed instructions and data temporarily. This reduces the time the processor waits for information. An optical disc, hard disk, and magnetic tape are storage media that are generally slower and used for longer-term storage, not immediate processor access. Therefore, option A is correct.