Computer Fundamentals and System Concepts

A mode switch occurs when transitioning from user mode to kernel mode (or vice versa). This happens during system calls, interrupts, or exceptions - the process changes privilege levels but remains the same process.

The ready list (also called the ready queue) is the operating system data structure that holds the Process Control Blocks (PCBs) of all processes that are ready to execute. These processes have all required resources except the CPU and are waiting for processor time.

Both 'process descriptor' and 'process control block' are valid terms for the data structure that contains all information about a process. PCB is the more common textbook term, while 'process descriptor' is used in some systems like UNIX. They represent the same concept.

Processes have attributes such as priority, state (running, ready, blocked), PID, memory allocation, and resource holdings. These attributes are stored in the Process Control Block (PCB) and enable the OS to schedule, manage, and control process execution.

It is abbreviation for Transmitter Empty.This component in Intel 8251 microprocessor is an output terminal which indicates that the 8251 has transmitted all the characters and has no character data.

This capability performed by computer is used to store information provided before or during the interrogation.

Trace-driven simulation processes recorded event traces from actual system execution, using real-world data as input to study system behavior patterns without affecting the production environment. Self-driven simulation generates synthetic workloads instead.

A 'number crunching' computer is specifically designed for heavy numerical computations and mathematical processing. While it excels at handling large volumes of numbers, it can also process other types of data. The term 'only numbers' (option D) is incorrect because such computers are not limited exclusively to numerical data.

The Whirlwind computer (developed at MIT, operational in 1951) was the first electronic stored-program computer to use magnetic core memory. Core memory replaced vacuum tubes and Williams tubes, offering faster, more reliable storage. The IBM 701 used Williams tube memory initially.

Historically, many supposed 'computer errors' were actually human data entry mistakes - incorrect keystrokes, transposed numbers, wrong values entered. The phrase 'garbage in, garbage out' (GIGO) became famous because flawed input produces flawed output regardless of computer correctness. Programming bugs (software errors) and hardware failures do occur, but data entry errors were historically most common.

Computer generations are categorized by their primary electronic technology: First generation (1940s-1950s) used vacuum tubes; Second generation (late 1950s-1960s) used transistors; Third generation (1960s-1970s) used integrated circuits (ICs); Fourth generation (1970s-present) uses very large-scale integration (VLSI) and microprocessors. Therefore, transistors characterize the second generation.

Option 4 is the correct answer.

Dumb terminal provides keyboard input and screen output and no data processing capability.

A mainframe computer is a very large and expensive computer capable of supporting hundreds or even thousands of users simultaneously.