Basic computer operations (hardware and software)

When a computer is switched on, firmware performs an initial hardware check, commonly called POST, to verify essential components such as memory and the processor. If this preliminary check succeeds, the boot process finds and loads the operating system. Therefore option B gives the correct sequence. The other options place software or unrelated devices before the essential startup checks.

A program can close immediately because the computer does not meet its required memory, processor, operating-system version, or other compatibility conditions. Corrupted files, missing dependencies, or an internal software error can produce the same symptom. Hence option C is the most reasonable answer. Screen colour, mouse size, and an ordinary long folder name do not normally cause an installed application to exit immediately.

A device driver is system software that translates communication between an operating system and a particular hardware device. If the driver is missing, incompatible, outdated, or corrupted, the operating system may fail to identify or use the connected device. Therefore option B is correct. A file name, monitor brightness, or the number of desktop icons does not normally control hardware recognition.

The governing concept is the software-layer relationship. An operating system manages the processor, memory, storage and input-output devices, and offers services such as file handling and program execution. Application software uses these facilities instead of controlling every device directly. It is not hardware, does not depend on printers, and files need not be online. Thus option B is correct.

The governing concept is that system performance depends on interacting components rather than one part alone. CPU architecture and speed matter, but available RAM, storage technology and capacity, operating-system condition, background programs and software efficiency also affect response time. The monitor and printer do not perform the computer's main calculations, and the CPU is essential. Hence option A is correct.

The governing concept is diagnostic use of an operating-system utility. Task Manager can display running processes and their CPU, memory, disk or network usage. By sorting these values, a user can identify a program consuming unusual resources and then investigate or close it when appropriate. It does not print files, replace cables or transform hardware. Therefore option B is correct.

The governing concept is malware containment. Quarantine moves a suspicious file to a restricted location or changes its ability to run, reducing the chance that it will infect other files or alter the system. The file is not being made public, printed or merely renamed. It may later be deleted or restored after review, so quarantine should not be confused with permanent deletion. Thus option D is correct.

The governing concept is lawful and responsible software use. Most commercial software is supplied under a licence that defines who may use it, on how many devices and under what conditions. An unauthorised copy may breach copyright or licence terms and can also come from an unsafe source containing malware. It does not automatically improve speed, extend hardware life or reduce file size. Therefore option A is correct.

The governing concept is backup completeness. Before formatting, a user should preserve not only visible documents but also application settings, configuration files, licenses where relevant, and other important data. Therefore, option C is correct: copying only selected files can leave the system difficult to restore. File size, image type, or a clear folder name does not determine whether the backup is complete.

The governing concept is storage technology. An SSD stores data in flash memory and accesses it electronically, whereas a traditional HDD uses spinning platters and a moving read/write head. Removing those mechanical movements can reduce access time and improve responsiveness, so option A is correct. An SSD still needs power, can store many file types, and is not the same as RAM.

The governing concept is the difference between storage capacity and active system performance. Free disk space indicates how much data can be stored; it does not guarantee sufficient RAM, processor capacity, or efficient software. Option B is correct because memory pressure, a busy CPU, background tasks, or a program fault can slow execution. The other options do not logically affect processing speed in this situation.

The governing concept is lossy compression. It reduces file size by permanently removing some information, which can lower image sharpness or audio fidelity, especially after repeated saving. Option D is correct because pictures and sound can visibly or audibly lose quality. Lossless compression preserves the original data, while renaming, copying, or placing a text file in a folder does not itself reduce quality.

The governing concept is temporary unresponsiveness. A program may appear frozen while it is saving, loading a large file, processing data, or waiting for another resource. Waiting briefly can allow it to finish and reduces the risk of losing unsaved work, so option D is correct. Force-closing does not guarantee saving; the other options are unrelated or falsely claim automatic saving.

The governing concept is backup redundancy: a backup protects data only when it is stored independently from the original. If the disk fails, is damaged, or becomes inaccessible, both copies on that same disk can disappear together. Therefore, option A is correct. Options B, C, and D do not describe the effect of a disk failure; a separate drive, external medium, or cloud location would provide better protection.

The governing concept is file compatibility and data integrity. Programs may use different formats, features, or editing rules; when both change the same file, some content can be altered, lost, or displayed differently. Thus, option C is correct because inconsistent formatting or content may result. Monitor brightness, printer paper, and mouse damage are unrelated hardware effects and do not logically follow from editing a file with two programs.

The governing concept is safe shutdown. The operating system must close programs, update file information, and finish writing buffered data before power is removed. Cutting power interrupts these steps, so unsaved work may disappear and file-system data may become corrupted. Option D is correct. The other options describe impossible changes to unrelated devices and are not consequences of switching off the power abruptly.

The governing concept is the input-process-output model. Even when the intended instruction is correct, an error can arise from incorrect input data, a formula, a program condition, or another part of the processing logic. Option C is therefore the appropriate level to examine first. A monitor stand, mouse pad, or printer cable does not normally determine the result of an internal calculation.

The governing concept is thermal management and resource load. A fan speeds up when internal temperature rises or when the processor is working heavily, such as during demanding software, background tasks, blocked airflow, or malware activity. Thus, option D is correct, although the fan alone does not prove one exact cause. File names, icon counts, and printer paper do not normally control the computer’s cooling fan.

The governing concept is symptom-based troubleshooting. When only a few keys fail, the first checks should focus on the keyboard itself: dust under the keys, liquid or physical damage, a loose connection, or an accessibility and layout setting. Option B is the most appropriate initial conclusion, but it is not proof of one exact fault. A complete operating-system failure, hard-disk damage, or monitor resolution would not usually affect only selected keys.

The governing concept is that a mouse has separate functions: movement is detected by its sensor, while clicking depends on the buttons, switches, driver, or related settings. Since the pointer moves, the sensor and basic connection are probably working. Therefore, option C best matches the symptom. A monitor, hard disk capacity, or printer-ink problem would not normally prevent mouse clicks from being registered.

The governing concept is display troubleshooting: image sharpness depends mainly on the monitor connection, display settings, and suitable screen resolution. If the computer operates normally but the picture is blurry, these output-related causes should be checked first. Option D is correct because it addresses both a possible loose or faulty video connection and an unsuitable resolution. File extensions, licences, and the Recycle Bin do not control image clarity.

The governing concept is software and operating-system compatibility. Older applications may expect earlier system settings, libraries, or behaviours that a newer operating system handles differently. Compatibility mode imitates selected older conditions so the application has a better chance of running correctly. Option C is therefore correct. Renaming a file, stopping mouse movement, or changing a printer into a scanner does not solve a version-compatibility problem.

The governing concept is software repair. If essential program files are corrupted, incomplete, or missing, reinstalling the application can replace them with a fresh, consistent set of files and restore normal operation. Option D is correct, although simpler repairs or an official repair tool may sometimes be tried first. A loose monitor stand, dusty keyboard, or low printer-paper supply is a physical-device issue and does not require reinstalling software.

The governing concept is safe file handling. A filename can be misleading, and a harmful executable may be disguised with an attractive document-like name. Before opening an unfamiliar file, the user should consider its source, inspect the complete extension when possible, scan it with trusted security software, and avoid unexpected attachments. Option D is correct; monitor brightness, folder colour, and printer checks do not establish file safety.

Computer maintenance requires coordinated care of both hardware and software. Regular updates can fix defects and security weaknesses, scans can detect harmful programs, backups protect important data, and cleaning supports proper airflow and operation. Therefore, option A is correct because it combines preventive software and hardware practices. Cleaning only the screen is incomplete, deleting programs daily is unnecessary, and avoiding updates increases risk.