Class 11 Computer Science
Chapter 1 – Computer System
📘 Download PDF1.1 Introduction
A computer system is an integrated set of hardware and software designed to process data and produce useful results.
1.2 Components of Computer System
Major components include:
- Input devices: Keyboard, Mouse, Scanner
- Output devices: Monitor, Printer, Speaker
- Memory: RAM (temporary), ROM (permanent)
- Storage: Hard drive, SSD
- Processor: CPU (ALU + CU)
1.3 Software and its Types
Software is a set of instructions that tell a computer what to do. It is broadly classified into:
- System software: Operating system, device drivers, utilities
- Application software: Word processors, web browsers, games
1.4 Operating System
An operating system (OS) is system software that manages computer hardware and software resources and provides services for computer programs.
- Acts as an interface between user and hardware
- Manages files, processes, and memory
1.5 Computer Languages
Computer languages are used to write programs. Types include:
- Machine Language (Binary)
- Assembly Language (Low-level)
- High-level Languages (C, C++, Python, Java)
1.6 Number System
Understanding different number systems is crucial:
- Decimal (Base 10)
- Binary (Base 2)
- Octal (Base 8)
- Hexadecimal (Base 16)
1.7 Logic Gates
Logic gates are basic building blocks of digital circuits:
- AND Gate – Output is 1 only if both inputs are 1
- OR Gate – Output is 1 if any input is 1
- NOT Gate – Inverts the input
🧠 Quiz Time
- Q1. Name the main components of a computer system.
- Q2. Differentiate between RAM and ROM.
- Q3. What is the function of an operating system?
- Q4. Convert 45 (Decimal) to Binary.
- Q5. Which gate gives output 1 only when both inputs are 1?