Computer Science MCQS

RAID stands for Redundant Array of Independent Disks (originally Inexpensive Disks). Its primary purpose is to enhance storage performance by distributing data across multiple drives. By doing so, RAID can offer several benefits:

• Improved performance: Data can be read from or written to multiple disks simultaneously.
• Data redundancy/fault tolerance: In some RAID levels, data is duplicated or parity information is stored, allowing data to be recovered even if one or more drives fail.

An Ethernet card, which is used to set up a wired network connection, is also commonly known as a Network Interface Card (NIC). The NIC is a hardware component that allows a computer to connect to a network using a wired connection, typically via an Ethernet cable.

This is an analogy question. A lock provides security or access control for a door. Similarly, a password provides security or access control for a computer (or an account/system within a computer). Just as a lock restricts physical entry, a password restricts digital access.

The primary purpose of indexing in databases is to speed up data search and retrieval operations. An index is a special lookup table that the database search engine can use to quickly find data. Much like an index in a book, it points to the location of specific data records without having to scan the entire table, significantly reducing query execution time for large datasets.

A Worm is a standalone malware computer program that replicates itself in order to spread to other computers. It often uses a computer network to spread itself, relying on security vulnerabilities on the target computer to access it. Unlike a virus, a worm does not need to attach itself to an existing program or require user interaction to spread.

• Virus: Requires a host program and user action to execute and spread.
• Trojan: Disguises itself as legitimate software but carries out malicious activities, relying on user deception.
• Spyware: Gathers information about a person or organization without their knowledge and transmits it to another entity.

In computer operating systems, checkpoints are critical for the recovery process. A checkpoint is a point in time where the state of a system or application is saved. This allows the system to be restored to that specific state in case of a failure, preventing loss of data or progress and facilitating a quicker recovery.

In Microsoft PowerPoint, a presentation is fundamentally a collection of slides. Each slide is an individual page that can contain text, images, charts, videos, and other multimedia elements, all organized to convey information or a message to an audience.

The correct answer is D: .pdf. While Microsoft Excel can export data to a PDF (Portable Document Format) file, .pdf is not a native or valid Microsoft Excel *file format* for storing editable spreadsheet data. PDF is a universal file format used to present documents in a manner independent of application software, hardware, and operating systems. When you save an Excel sheet as a PDF, it essentially creates a snapshot or print-ready version, not a functional spreadsheet file that can be fully reopened and edited in Excel with all its formulas and sheet structure intact.

• A: .xlsx is incorrect. .xlsx is the primary and default file format for Microsoft Excel documents starting from Excel 2007. It is an XML-based format that supports all modern Excel features.
• B: .csv is incorrect. .csv (Comma Separated Values) is a widely used plain-text file format that stores tabular data in rows and columns, where each value is separated by a comma. Excel can open, edit, and save .csv files, making it a valid and common format for data exchange with Excel.
• C: .xls is incorrect. .xls is the traditional file format for Microsoft Excel workbooks from Excel 97 to Excel 2003. Although superseded by .xlsx, it is still a valid and recognizable Excel file format that modern Excel versions can open and save.

The correct answer is B: 80. The HTTP (Hypertext Transfer Protocol) protocol, which is the foundation of data communication for the World Wide Web, works on port 80 by default. When you type a web address (e.g., http://www.example.com) into your browser without specifying a port number, your browser automatically attempts to connect to port 80 on the web server to retrieve the webpage. This standardization allows for seamless web browsing.

• A: 21 is incorrect. Port 21 is the default port for FTP (File Transfer Protocol), which is used for transferring files between a client and a server on a computer network. It is not used for HTTP communication.
• C: 25 is incorrect. Port 25 is the default port for SMTP (Simple Mail Transfer Protocol), which is used for sending and receiving email messages between email servers. It is not used for web browsing.
• D: 443 is incorrect. Port 443 is the default port for HTTPS (Hypertext Transfer Protocol Secure). HTTPS is the secure version of HTTP, using SSL/TLS encryption to secure communication over a computer network. While related to web browsing, it is for secure connections, whereas HTTP's default is port 80 for unencrypted communication.

The correct answer is C: Protocol Network. Protocols are sets of rules that define how data is formatted, transmitted, received, and processed during communication between computers or devices in a network. They establish common ground and ensure that all participating devices can understand and interpret the exchanged information. Without protocols, computers would be unable to communicate effectively or meaningfully, leading to chaos in data transmission.

• A: Hardware is incorrect. Hardware refers to the physical components of a computer system, such as network cards, routers, and cables. While hardware is essential for establishing physical connections and transmitting signals, it does not define the logical rules for how information is structured and interpreted during communication.
• B: Operating System is incorrect. An operating system (OS) is software that manages computer hardware and software resources and provides common services for computer programs. While an OS implements network protocols, it doesn't *define* the universal rules for communication between *all* computers across a network; protocols do that independently of specific OS implementations.
• D: Software is incorrect. Software is a broad term encompassing all programs and applications that run on a computer. While network protocols are implemented in software, the term "software" alone is too general. It doesn't specifically pinpoint the defining rules for communication between computers in the way that "Protocol Network" (or simply "Protocol" in this context) does.