Tech+ Practice Questions

The Waterfall methodology is a linear, sequential approach to software development. It is best suited for projects where requirements are well-understood, documented, and stable. Since the requirements are fixed and changes are unlikely, the structured, phase-by-phase nature of Waterfall (Requirements -> Design -> Implementation -> Testing -> Deployment) provides predictability in terms of schedule and budget. Agile and Scrum are iterative methodologies designed to accommodate changing requirements, which is not a primary concern here.

A primary key is a constraint in a relational database that uniquely identifies each record (row) in a table. By definition, a primary key column cannot contain NULL values and every value must be unique. This directly addresses the requirement to uniquely identify each customer and prevent duplicates. A foreign key is used to link two tables together. A unique constraint ensures uniqueness but allows one NULL value, and a check constraint validates data, but neither serves as the primary identifier.

JSON is the ideal format for this use case. It is lightweight, human-readable, and its structure directly maps to JavaScript objects, making it trivial to parse in a browser. It natively supports nested objects and arrays, which is a key requirement. CSV is only suitable for simple, tabular data. XML can handle complex data but is more verbose and requires more effort to parse compared to JSON. SQL is a query language, not a data interchange format.

Implementing daily incremental backups is the best solution. An incremental backup only copies files that have changed since the last backup of any type. This means the daily backups will be very small and fast. In a disaster recovery scenario, they would restore the last full backup (from Friday) and then each incremental backup in order (Monday, Tuesday, etc.). This strategy significantly reduces the Recovery Point Objective (RPO), minimizing data loss, while also minimizing the daily backup time and storage space required.

The principle of least privilege dictates that users, programs, or processes should be given only the minimum levels of access – or permissions – needed to perform their job functions. This is a fundamental concept in information security designed to limit the damage that can be caused by an accident, error, or malicious attack.

Phishing is a type of social engineering attack where attackers attempt to trick users into revealing sensitive information (like usernames, passwords, or credit card details) by disguising themselves as a trustworthy entity in an electronic communication. The key elements described—urgency, impersonation of a trusted entity, a suspicious link, and poor grammar—are all common red flags of a phishing email.

An IP address in the 169.254.x.x range is an Automatic Private IP Addressing (APIPA) address. Windows assigns itself an APIPA address when it is configured for DHCP but cannot reach a DHCP server to obtain an IP address lease. This indicates a problem with the DHCP server itself or a connectivity issue between the client PC and the server (such as a bad cable, faulty switch port, or VLAN misconfiguration).

The beep codes are part of the Power-On Self-Test (POST) and indicate a specific hardware failure detected by the BIOS/UEFI. The first step in establishing a theory of the problem is to understand what these codes mean. The motherboard manual provides the key to deciphering these codes, which typically point to issues with RAM, CPU, or the video card. Reinstalling the OS is irrelevant as the system is not even reaching the bootloader. Replacing the power supply or checking cables are plausible but less precise than first interpreting the specific error code the system is providing.

Network connection speed, or bandwidth, is measured in bits per second. For modern office internet connections, megabits per second (Mbps) or gigabits per second (Gbps) are the standard units. Gigabytes (GB) measure data storage capacity. Gigahertz (GHz) measures processing speed (like a CPU's clock cycle). Terabytes (TB) is a larger unit of data storage.

The address format, consisting of six pairs of characters (0-9 and A-F) separated by colons, is characteristic of a MAC (Media Access Control) address. MAC addresses are represented using the hexadecimal (base-16) notational system. They are unique hardware identifiers for network interface cards (NICs). IPv4 addresses use decimal notation, and subnet masks are represented in either decimal or binary.