Explanation: The memory occupied by float a; depends on the system and compiler: On most systems (32-bit and 64-bit): float typically occupies 4 bytes. If using double instead of float: It usually occupies 8 bytes. Since the question specifies float a;, the correct answer is 4 bytes.

Explanation: All digital computers represent data as discrete signals using binary digits (bits), which can be either 0 or 1. These bits are used to encode various types of information, including numbers, letters, symbols, and instructions. This binary system allows digital computers to perform complex calculations, store data, and execute programs efficiently.

Explanation: A Microcomputer is commonly referred to as a PC (Personal Computer) and is designed for individual use. It includes desktops, laptops, and tablets. Mainframe computers are large and powerful systems used for enterprise-level applications. Minicomputers (also known as mid-range computers) were used earlier but are now mostly replaced by servers and high-performance PCs.

Explanation: Microprocessors were introduced as switching devices in Fourth Generation computers (1970s–present). Generations of Computers and Their Switching Devices: First Generation (1940s–1950s) – Used vacuum tubes. Second Generation (1950s–1960s) – Used transistors. Third Generation (1960s–1970s) – Used integrated circuits (ICs). Fourth Generation (1970s–present) – Used microprocessors. Thus, Fourth Generation computers marked the beginning of modern PCs with microprocessor-based architecture.

Explanation: Ring, Bus, and Star are topologies (ways to arrange network devices). PAN (Personal Area Network) is a type of network used for short-range communication, such as Bluetooth and Wi-Fi connections between personal devices (smartphones, laptops, etc.).

Explanation: LAN (Local Area Network) is a network that connects computers and devices within a limited geographical area, such as a home, office, or school. It allows fast and secure communication between connected devices.