Computer Fundamentals and System Concepts

Resident viruses dwell permanently in RAM (Random Access Memory) after the initial infection, allowing them to remain active and infect other files. Hard disk and boot sector are storage locations where viruses can reside but are not where resident viruses specifically 'dwell' during active operation.

Polymorphic viruses constantly change their code (encrypt and decrypt) while keeping the functionality intact, making them impossible to detect using fixed string or signature searches. Each infection looks different to signature-based antivirus. Resident, Boot sector, and Macro viruses can be detected with signature-based methods.

Trojan Horses and Logic Bombs are non-replicating malware - they require execution and don't self-copy. Overwrite Viruses replicate by infecting files, Worms self-replicate across networks. Only B and D lack self-replication capability, making them the correct MC-2 answer.

Companion viruses exhibit characteristics of both Resident Viruses (which install in memory and infect files) and Direct Action Viruses (which infect files when executed and then remain dormant). They don't have properties of boot sector viruses, overwrite viruses, or directory viruses as their primary characteristics.

The ILOVEYOU virus (May 2000) caused estimated $10-15 billion in damages globally, infecting millions of computers via email with the subject 'ILOVEYOU'. Melissa (1999) was damaging but less widespread. Code Red (2001) targeted servers, and Chernobyl/CIH (1998) was destructive but not as economically damaging.

ENIAC (Electronic Numerical Integrator and Computer) was the first general-purpose electronic digital computer, completed in 1945 and formally dedicated in February 1946 at the University of Pennsylvania. Harvard Mark I was electromechanical, not fully electronic.

ENIAC is widely regarded as the first electronic general-purpose computer. The question is somewhat ambiguously worded - 'first computer' could mean different things, but ENIAC was the first all-electronic digital computer, unlike earlier electromechanical devices.

Blaise Pascal invented the Pascaline in 1642, an early mechanical calculator that could perform addition and subtraction. It was one of the first calculating machines and used a geared wheel mechanism. His work laid groundwork for future computing devices.

Downloading refers to retrieving data from a remote server to your local device. It is the opposite of uploading, which is sending files from your device to the Internet. Options like scanning or moving files from local media are unrelated to network transfers.

Degaussing is the process of reducing or eliminating a magnetic field, specifically used to erase data from magnetic storage media like floppy disks, tapes, or hard drives. It is not related to CPU attachments, creating media, or medical applications.

Computer viruses are malicious programs that spread through file sharing, email attachments, infected downloads, or network connections. A scanner is an input device for digitizing physical documents - it cannot contract or spread viruses as it does not execute or transfer program files.

The Intel Pentium FDIV bug was a flaw in the Floating Point Unit (FPU) of certain Pentium processors that caused incorrect division results. It was not related to cache, socket issues, and Intel acknowledged the flaw.

Cache is a type of high-speed memory that stores frequently used data for quick access. PS (power supply), DSP (Digital Signal Processor), and FLOPS (Floating Point Operations Per Second - a performance measure) are not directly related to memory. Cache memory is essential for CPU performance.

The motherboard is the main printed circuit board in a computer. It is also commonly referred to as the 'system board' or 'mainboard'. CPU refers to the processor, and 'Fatherboard' is a non-existent humorous term.