Basic computer operations (hardware and software)

An incremental backup copies files that are new or changed since the immediately preceding backup, whether that preceding backup was full or incremental. Consequently, each individual backup is usually smaller and faster. Option A describes a full backup, and option B describes a differential backup, which includes changes since the last full backup. Option D is not guaranteed because backup media may be local or online.

The process scheduler is an operating-system component responsible for deciding which ready process receives processor time and for how long. It supports multitasking by switching the processor among processes according to scheduling rules and priorities. Option C is correct. A text editor is an application, a printer driver serves printing, and a scanner captures input; none allocates CPU time among all processes.

The governing security concept is least privilege: software should receive only the permissions needed for its task. Administrator rights can allow an application to change protected settings, install components, access sensitive data, alter accounts or damage system files. A suspicious program could misuse that authority, so the risk is much broader than changing colour, playing music or resizing a screen. Option C is correct.

The governing concept is compatibility between software, device drivers and hardware. An update may require a newer driver, change supported interfaces or remove support for an old device. If the existing driver cannot communicate correctly with the updated software, the device may stop responding until a compatible driver, rollback or supported update is installed. File-name length, brightness and key count do not explain this pattern, so B is correct.

The startup hardware check, commonly called POST, occurs before the operating system is loaded. If that check finishes but loading stops afterward, attention should move to the selected boot device, storage access, boot records, or operating-system files. Thus option A is correct. A mouse pad, speaker volume, or monitor brightness does not normally control whether the operating system can start.

A device driver is software that allows the operating system to communicate with hardware. After a new operating system is installed, an older printer driver may be incompatible, causing detection or printing failures. Updating the driver can restore communication, so option C is correct. An unstable table, empty paper tray, or dusty screen requires a physical or consumable remedy, not a driver update.

During a normal boot, firmware starts first and performs initial hardware checks, then locates and starts a boot loader. The boot loader finds the operating system and loads its essential startup components into memory, after which control passes to the operating system. Therefore A gives the correct control sequence; B reverses the stages, C starts too late, and D places the operating system before the required test and loader.

POST checks whether essential hardware can initialize; it does not itself provide an operating system. After POST succeeds, firmware searches the configured devices for bootable instructions. If none contains a valid boot loader or operating system, startup cannot continue and the computer normally displays a boot-device or operating-system-not-found error. Thus B is correct, whereas the other results do not follow from a missing boot device.

A boot loader is a small program started during the boot process. Its central function is to locate the operating system, place its kernel or essential startup code into main memory, and transfer control to it. Option C is therefore the precise answer. Backups, driver removal, and disk formatting are separate maintenance or storage operations and are not the boot loader’s normal purpose.

Firmware follows the boot order to decide which storage or removable device to examine first. If a USB drive, network source, or empty device is placed before the drive containing the valid operating system, the computer may search that source first, show an error, or delay startup. Option D is correct; boot order does not change display resolution, keyboard data, or RAM’s temporary nature.

When physical RAM is under pressure, an operating system can use a reserved portion of secondary storage as virtual memory. It moves less-active memory pages to that space and retrieves them when needed, allowing programs to continue running. Option C is correct, although storage is much slower than RAM, so heavy paging can cause noticeable performance loss. The other options do not solve memory pressure.

High RAM usage means active programs are consuming most of the available working memory. When storage activity rises at the same time, the operating system is likely paging data between RAM and a storage device because it lacks enough physical memory. This heavy virtual-memory use explains the slowdown, so D is correct. Speaker volume, display resolution, and printer paper do not produce this characteristic pair of symptoms.

A backup job may report success even when files are incomplete, corrupted, inaccessible, or recorded with an unusable catalog. A restore test reads selected backup data and attempts to recover it to confirm that the backup is usable when needed. Therefore, option D is correct. The other choices describe unrelated hardware effects and cannot establish data recoverability.

A partition is a logical section of a storage device, not an independent physical device. If the drive suffers mechanical failure, electrical damage, fire, or serious corruption, every partition on it may become unavailable, including the backup. Option A is therefore correct. The other options are false: partitions can store files, are not automatically read-only, and are normally visible to the operating system.

Ordinary deletion usually removes the file-system reference, marking the occupied space as available for reuse, rather than immediately overwriting every stored bit. Until that space is reused or securely erased, recovery tools may retrieve fragments or the complete file. Therefore, option D is correct. The other choices wrongly attribute storage behavior to the internet, monitor, or printer.

Antivirus is one layer of defence, but effective security also requires current virus definitions and software patches, cautious handling of links and attachments, strong access practices, and reliable backups. New or disguised threats may evade an outdated scanner, while unsafe user actions can permit infection. Therefore, option B is correct; the other statements are technically false or irrelevant.

The governing concept is the relationship between a foreground application and its background service. Services may handle synchronization, updates, notifications, licensing checks, indexing, or other supporting tasks. If such a service stops, the visible application may remain open but dependent features can fail or become unavailable. Display color, storage capacity, and keyboard size are not normal effects of stopping a service.

The governing concept is direct memory access, or DMA. A DMA controller allows an input/output device to transfer a block of data directly to or from main memory, while the processor is freed from supervising every byte. The processor may configure the transfer and receive a completion signal, so it is not completely uninvolved. DMA does not make memory non-volatile, encrypt files, or change a monitor into storage.

The governing concept is CPU scheduling. A scheduler uses priority when deciding which ready process should receive processor time. Raising a process's priority may let it run sooner or receive more opportunities than ordinary processes, although it does not create extra CPU power and results depend on the operating system. Option B is correct; file permanence, memory expansion, and monitor color are unrelated.

The governing concept is dynamic memory management. A process requests memory while it runs and should release that memory when it no longer needs it. In a memory leak, the program loses track of allocated memory or fails to return it, so repeated operations gradually reduce the memory available to the system. This can cause slowing, errors, or a crash. It is not electrical leakage, water damage, or a monitor fault, making B correct.

Computer performance depends on several resources, not only the processor. If a disk or other storage device has slow input-output, programs may remain blocked while waiting for data, so CPU usage can stay low even though the computer feels unresponsive. Therefore option C is correct. Monitor color, keyboard cleanliness, and the number of mouse buttons do not create this resource bottleneck.

The governing concept is identifying a bottleneck by comparing resource utilization. When processor usage is high but graphics usage is low, the processor may be unable to prepare game logic, physics, or draw commands quickly enough, leaving the graphics unit underused. Thus, option C is the best conclusion, although further testing is useful. The data do not prove a faulty graphics card, and the other choices are unrelated or impossible.

The governing concept is virtual memory and paging. RAM holds actively used application data, but when many programs require more memory than is available, the operating system moves less-used pages to storage and brings them back when needed. Repeated transfers create high drive activity and slow responses. Therefore, option D is correct. RAM does not control a printer, change monitor size, or permanently store all files.

The governing concept is targeted upgrading based on workload analysis. Different tasks stress different resources: games may need graphics performance, data processing may need processor speed, and multitasking may need more RAM. Measuring the actual workload reveals the limiting component and prevents spending money on an upgrade that will not help. Therefore, option A is correct; case colour, file names, and printer ink do not identify system performance needs.