A+ - PC Parts

Explanation
The motherboard, CPU, memory, and video card are considered essential components of a computer. The motherboard serves as the main circuit board that connects all the other components together. The CPU (Central Processing Unit) is the brain of the computer, responsible for executing instructions and performing calculations. Memory, also known as RAM (Random Access Memory), is used to temporarily store data and instructions that the CPU needs to access quickly. The video card, or graphics card, is responsible for rendering and displaying images and videos on the computer's monitor. A scanner, on the other hand, is not an essential component as it is an external device used for inputting physical documents or images into the computer.

Explanation
Activity lights, power switch, and USB ports are all devices that can be found on the front or back of a computer. Activity lights are used to indicate the status of various components such as the hard drive or network connection. The power switch is used to turn the computer on or off. USB ports are used to connect external devices such as keyboards, mice, or flash drives to the computer. Therefore, all of these options are correct.

Explanation
Overheating can cause a desktop computer to fail because excessive heat can damage the internal components and lead to system shutdowns or permanent damage. Loose add-on cards can also cause failure as they may become dislodged or cause connectivity issues, resulting in system instability or failure. Drive failures can cause a computer to fail as it may result in data loss or the inability to access important files. Adding more memory, however, does not typically cause a desktop computer to fail as long as it is compatible and properly installed.

Explanation
Windows XP, Windows 2000, and Windows Vista are the most commonly used Windows operating systems. These three versions of Windows have been widely adopted and used by individuals and businesses alike. Windows XP was particularly popular and widely used for a long time until its support ended in 2014. Windows 2000 was also widely used, especially in business environments. Windows Vista, although not as popular as XP, was still commonly used before the release of Windows 7.

Explanation
CHKDSK and Disk Defragmenter are the two best answers because they are both utilities that can be used on a standard Windows computer for regular maintenance and optimization. CHKDSK (Check Disk) is used to scan and fix errors on the hard drive, while Disk Defragmenter is used to reorganize fragmented files on the hard drive, improving overall system performance.

Explanation
The first thing you should do when replacing a PCI card is to shut down the system and unplug the power. This is important to ensure that there is no electrical current running through the system, which can prevent any damage to the components and ensure your safety while working on the hardware. Opening the case, opening the package, or purchasing the device are all steps that come after shutting down and unplugging the power.

Explanation
When opening the case to access the internal parts of a computer, it is important to check the system manual. This is because the manual provides specific instructions and guidelines for safely opening the case and accessing the internal components. It may also provide information on any special precautions that need to be taken or specific steps that need to be followed. By checking the system manual, the user can ensure that they are properly informed and can avoid any potential damage or problems when accessing the internal parts of the computer.

Explanation
Touching the unpainted metal of the chassis helps in preventing ESD because it allows the person to discharge any static electricity they may have built up before touching sensitive electronic components. Wearing an antistatic wrist strap also helps in preventing ESD as it grounds the person and prevents the buildup of static electricity.

Explanation
The correct answer is "There is a twist at one end." This is because floppy drive cables typically have a twist in the cable near one end. This twist is used to indicate which end of the cable should be connected to the floppy drive. The twist helps ensure that the cable is properly aligned and connected to the correct pins on the drive.

Explanation
To prevent the VGA cable from losing connection, you should attach it to the video card by turning the thumbscrews. Thumbscrews are designed to secure the cable firmly in place, providing a stable connection. By turning the thumbscrews, you can tighten the cable and ensure that it stays securely attached to the video port, minimizing the risk of disconnection.

Explanation
Onboard and addon card devices both use IRQ, DMA, Memory, and I/O port as types of hardware resources. IRQ (Interrupt Request) is used to handle hardware interrupts, DMA (Direct Memory Access) allows devices to transfer data directly to and from memory without involving the CPU, Memory is used for storing data and instructions, and I/O port is used for communication between devices and the CPU.

Explanation
Direct Memory Access (DMA) is the process of bypassing the CPU and allowing external devices to directly access the system's memory. This enables faster data transfer between the device and the memory without involving the CPU in every data transfer. DMA is commonly used in devices like sound cards, network cards, and hard drives to improve performance and reduce CPU overhead.