CBSE Class 11 Informatics Practices Unit 1 MCQs with Answers | Introduction to Computer System

Preparing for your CBSE Class 11 Informatics Practices examination? Practice these carefully selected 25 Multiple Choice Questions (MCQs) based on the latest CBSE syllabus (2026–27). These questions cover computer evolution, hardware components, input/output devices, memory, software, data deletion and recovery, and security concerns.

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Introduction to Computer System MCQs

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Q1. Which of the following is known as the brain of the computer?

A. Keyboard
B. Monitor
C. CPU
D. Mouse

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Answer: C. CPU

Explanation: The CPU (Central Processing Unit) executes instructions, performs calculations, and controls all operations of the computer. Therefore, it is known as the brain of the computer.

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Q2. Which technology was used in the first generation of computers?

A. Transistors
B. Integrated Circuits
C. Vacuum Tubes
D. Microprocessors

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Answer: C. Vacuum Tubes

Explanation: First-generation computers (1940s–1950s) used vacuum tubes, making them large, expensive, and power-consuming.

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Q3. Which generation of computers introduced microprocessors?

A. First Generation
B. Second Generation
C. Third Generation
D. Fourth Generation

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Answer: D. Fourth Generation

Explanation: The invention of the microprocessor marked the beginning of fourth-generation computers, making computers smaller, faster, and more affordable.

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Q4. Which component of the CPU performs arithmetic and logical operations?

A. RAM
B. ALU
C. ROM
D. Hard Disk

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Answer: B. ALU

Explanation: The Arithmetic Logic Unit (ALU) performs all arithmetic calculations and logical comparisons.

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Q5. Which of the following is an input device?

A. Monitor
B. Printer
C. Keyboard
D. Speaker

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Answer: C. Keyboard

Explanation: A keyboard is an input device used to enter text, numbers, and commands into a computer.

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Q6. Which of the following is an output device?

A. Mouse
B. Scanner
C. Monitor
D. Microphone

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Answer: C. Monitor

Explanation: A monitor displays processed information and results produced by the computer.

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Q7. Which of the following is NOT an output device?

A. Plotter
B. Printer
C. Speaker
D. Scanner

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Answer: D. Scanner

Explanation: A scanner captures images or documents and sends them to the computer, making it an input device.

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Q8. Which memory loses its contents when the power is switched off?

A. ROM
B. Hard Disk
C. RAM
D. DVD

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Answer: C. RAM

Explanation: RAM is volatile memory, which means its contents are erased when the computer is turned off.

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Q9. Which type of memory permanently stores firmware such as BIOS?

A. RAM
B. Cache Memory
C. ROM
D. Register

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Answer: C. ROM

Explanation: ROM is non-volatile memory that permanently stores firmware like the BIOS program.

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Q10. Which of the following is an example of secondary memory?

A. RAM
B. Cache Memory
C. Hard Disk
D. Register

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Answer: C. Hard Disk

Explanation: Hard disks provide permanent storage for files, software, and operating systems, making them secondary memory devices.

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Q11. 1 Kilobyte (KB) is equal to:

A. 1000 Bytes
B. 1024 Bytes
C. 512 Bytes
D. 2048 Bytes

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Answer: B. 1024 Bytes

Explanation: In computer memory, 1 Kilobyte (KB) is equal to 1024 bytes because computers use the binary number system.

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Q12. Which of the following is the largest unit of memory?

A. KB
B. MB
C. GB
D. TB

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Answer: D. TB

Explanation: Among the given options, Terabyte (TB) is the largest memory unit.
1 TB = 1024 GB.

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Q13. Cache memory is mainly used to:

A. Store movies permanently
B. Increase processing speed
C. Store operating systems
D. Print documents

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Answer: B. Increase processing speed

Explanation: Cache memory stores frequently used instructions and data so that the CPU can access them quickly, improving overall performance.

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Q14. Which of the following is a characteristic of primary memory?

A. Large storage capacity
B. Directly accessed by the CPU
C. Used only for backup
D. Portable storage device

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Answer: B. Directly accessed by the CPU

Explanation: Primary memory (RAM and ROM) can be accessed directly by the CPU for faster processing.

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Q15. Deleted files can often be recovered because:

A. They are erased immediately.
B. Their storage location is marked as available until overwritten.
C. They are stored in ROM.
D. They remain permanently in RAM.

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Answer: B. Their storage location is marked as available until overwritten.

Explanation: When a file is deleted, its data usually remains on the storage device until new data overwrites that location.

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Q16. Which software is commonly used to recover deleted files?

A. Compiler
B. Antivirus Software
C. Data Recovery Software
D. Spreadsheet Software

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Answer: C. Data Recovery Software

Explanation: Data recovery software scans storage devices and attempts to restore deleted files that have not yet been overwritten.

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Q17. Which of the following is a security concern related to deleted data?

A. Slow Internet speed
B. Unauthorized recovery of deleted files
C. Low battery backup
D. Printer malfunction

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Answer: B. Unauthorized recovery of deleted files

Explanation: Sensitive data may be recovered by unauthorized users if it is not securely erased.

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Q18. Which type of software acts as an interface between the user and the computer hardware?

A. Application Software
B. Utility Software
C. System Software
D. Multimedia Software

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Answer: C. System Software

Explanation: System software, especially the operating system, manages hardware resources and provides a platform for application software.

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Q19. Which of the following is an example of system software?

A. MS Excel
B. Adobe Photoshop
C. Windows 11
D. VLC Media Player

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Answer: C. Windows 11

Explanation: Windows 11 is an operating system, which is a type of system software.

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Q20. Which of the following is application software?

A. Linux
B. Windows
C. Microsoft Word
D. BIOS

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Answer: C. Microsoft Word

Explanation: Microsoft Word is application software used for creating and editing documents.

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Q21. Software developed to perform a particular task is called:

A. Generic Purpose Software
B. Specific Purpose Software
C. System Software
D. Firmware

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Answer: B. Specific Purpose Software

Explanation: Specific purpose software is designed to perform a single or specialized task, such as payroll or billing software.

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Q22. Which of the following is an example of Generic Purpose Software?

A. Railway Reservation Software
B. School Management System
C. Microsoft Excel
D. Hospital Billing Software

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Answer: C. Microsoft Excel

Explanation: Microsoft Excel is a general-purpose spreadsheet application used for a variety of tasks by different users.

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Q23. Which component connects all the internal parts of a computer?

A. Hard Disk
B. Motherboard
C. Monitor
D. Scanner

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Answer: B. Motherboard

Explanation: The motherboard is the main circuit board that connects the CPU, memory, storage devices, and other hardware components.

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Q24. Which input device is commonly used to convert printed documents into digital form?

A. Printer
B. Plotter
C. Scanner
D. Projector

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Answer: C. Scanner

Explanation: A scanner captures printed text or images and converts them into digital format.

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Q25. Which statement best describes a computer?

A. A machine used only for calculations.
B. An electronic device that accepts input, processes data, stores information, and produces output.
C. A device used only for playing games.
D. A communication device only.

Show Answer

Answer: B. An electronic device that accepts input, processes data, stores information, and produces output.

Explanation: A computer is an electronic device that performs the IPO (Input-Process-Output) cycle while storing data and information for future use.

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