Computing Fundamentals Flashcards

A technician installs 8 GB of RAM in a laptop, but System Information reports only about 3.2 GB usable. The RAM modules test fine and are fully seated. What is the most likely cause?

Answer: A 32-bit edition of the operating system is installed, and it can address only about 4 GB in total, some of which is taken by hardware

A 32-bit operating system can address at most 2^32 bytes (4 GB) of memory space. Part of that space is set aside for hardware such as graphics memory and device I/O, so usable RAM often shows as about 3–3.5 GB. Installing a 64-bit OS fixes this. Integrated graphics does reserve some RAM, but normally hundreds of megabytes, not almost 5 GB. Mismatched module speeds make the RAM run at the slower speed but don't remove capacity. The page file size has no effect on how much physical RAM is detected.

A user buys an external drive advertised as 2 TB. When connected to Windows, File Explorer shows a capacity of about 1.81 TB. What best explains the difference?

Answer: The manufacturer counts with decimal units (1 TB = 10^12 bytes), but Windows counts with binary units (1 TiB = 2^40 bytes) while still labeling it 'TB'

Storage makers use decimal prefixes: 2 TB = 2,000,000,000,000 bytes. Windows divides by 1,099,511,627,776 (2^40), which gives about 1.82, and shows that as 'TB'. File system overhead is tiny by comparison. Factory-remapped sectors use spare areas and don't lower the advertised capacity. A brand-new external drive doesn't usually come with a hidden 10% recovery partition.

A company's IT policy says no one should run a traditional defragmentation tool on employee laptops that use solid-state drives (SSDs). Which reason best supports this policy?

Answer: SSDs can read any memory location equally fast, so defragmenting doesn't help performance and adds extra write cycles that wear the flash cells; the OS uses TRIM instead

Defragmenting helps hard drives because their read/write heads have to move physically to reach scattered pieces of a file. SSDs have no moving parts, so where the data sits barely affects speed. Rearranging files just adds writes, and flash memory supports only a limited number of write cycles. Modern operating systems 'optimize' SSDs by sending TRIM commands instead. SSDs can hold fragmented files, and defragmenting doesn't touch the firmware or the encryption.

After a user changes firmware settings, a PC refuses to load an older, unsigned bootloader for a secondary operating system. The message says the boot image failed verification. Which firmware feature is most likely causing this?

Answer: UEFI Secure Boot is enabled, so the firmware loads only bootloaders signed with trusted keys

Secure Boot is a UEFI feature that checks the digital signature of each boot component against trusted keys stored in the firmware. An unsigned or untrusted bootloader fails that check and is blocked. Legacy BIOS mode doesn't check signatures at all. Clearing the TPM can affect things like BitLocker keys, but it doesn't delete bootloaders. Fast Startup is a Windows hibernation-style feature, not a firmware signature check.

A development team wants to deploy its web application code to the cloud without installing, patching, or managing operating systems or runtime environments, while still controlling its own application code. Which cloud service model fits best?

Answer: Platform as a Service (PaaS)

With PaaS, the provider manages the servers, operating system, and runtime, and the customer deploys and manages its own application code. With IaaS, the customer still has to manage the OS and runtime. SaaS delivers a finished application that the customer only uses and doesn't write. DaaS delivers virtual desktops to end users, not a platform for hosting custom code.

A developer modifies a program released under the GNU General Public License (GPL) and plans to distribute the modified version to customers. What does the license require?

Answer: The source code for the modified version must be made available under the same GPL terms to the people who receive it

The GPL is a 'copyleft' license. Anyone who distributes a modified version must release it under the GPL and make the matching source code available to the people who receive it. The GPL does allow charging for distribution, since 'free' refers to freedom, not price. Keeping changes proprietary with only attribution is what permissive licenses like MIT allow, not the GPL. The GPL is specifically about access to source code, not just binaries.