Introduction to Computers — TN Class 11 Computer Science Exercise Solutions
Complete exercise solutions for the Tamil Nadu Board Class 11 Computer Science chapter Introduction to Computers. Every question type is covered with explanations.
How to Use This Page
1. Attempt each exercise on your own first — write your answer before looking at the solution. 2. Compare your answer — check reasoning and terminology against the solution provided. 3. Understand why — if your answer differs, figure out the concept you missed rather than just memorising. 4. Note recurring mistakes — maintain a small notebook of errors to revise before the exam. 5. Revise the Key Concepts table below before attempting the exercise section.
Key Concepts (Quick Recap)
| Concept | Details |
|---|---|
| Definition of a computer | An electronic device that accepts data as input, processes it, stores it, and produces information as output |
| IPO Cycle | Input → Process → Output — the fundamental operating cycle |
| Input Unit | Accepts raw data from the user (keyboard, mouse, scanner) |
| CPU | Brain of the computer; consists of ALU (arithmetic/logic operations) and Control Unit (coordinates all activities) |
| Memory Unit | Stores data, instructions, and results — Primary (RAM, ROM) and Secondary (HDD, SSD) |
| Output Unit | Presents processed information to the user (monitor, printer, speaker) |
| First Generation | Vacuum tubes, very large, high heat, unreliable — ENIAC, UNIVAC |
| Second Generation | Transistors, smaller, faster, more reliable — IBM 1401, CDC 1604 |
| Third Generation | Integrated Circuits (ICs), even smaller, cheaper — IBM 360, PDP-8 |
| Fourth Generation | Microprocessors (VLSI), personal computers — IBM PC, Apple II |
| Fifth Generation | AI, ULSI, parallel processing, natural language — ongoing |
| Supercomputer | Fastest, used for weather forecasting, nuclear simulations |
| Mainframe | Large, supports many users simultaneously, used in banks |
| Minicomputer | Mid-range, departmental use — PDP-11 |
| Microcomputer | Personal computers, laptops, tablets — most common type |
| Applications | Education (CAI, e-learning), Science (simulations), Business (accounting, inventory), Healthcare (diagnostics), Banking (ATM, NEFT), Entertainment (games, streaming), Government (e-governance) |
Key Abbreviations:
| Abbreviation | Full Form |
|---|---|
| ENIAC | Electronic Numerical Integrator and Calculator |
| UNIVAC | Universal Automatic Computer |
| EDSAC | Electronic Delay Storage Automatic Calculator |
| VLSI | Very Large Scale Integration |
| ULSI | Ultra Large Scale Integration |
| CPU | Central Processing Unit |
| ALU | Arithmetic and Logic Unit |
| RAM | Random Access Memory |
| ROM | Read Only Memory |
I. Choose the Best Answer (MCQs)
Q1. The first electronic computer was: (a) UNIVAC (b) ENIAC (c) EDSAC (d) MARK I
ENIAC (Electronic Numerical Integrator and Calculator), developed in 1946 by John Mauchly and J. Presper Eckert, is considered the first general-purpose electronic digital computer.
Q2. Which generation of computers used transistors? (a) First (b) Second (c) Third (d) Fourth
The Second Generation (1956–1963) replaced vacuum tubes with transistors, making computers smaller, faster, more energy-efficient, and more reliable.
Q3. The component that performs arithmetic and logical operations is: (a) Control Unit (b) ALU (c) Memory (d) Input Unit
The Arithmetic and Logic Unit (ALU) is the part of the CPU that carries out all arithmetic calculations (addition, subtraction, etc.) and logical comparisons (greater than, equal to, etc.).
Q4. Which type of computer is used for weather forecasting? (a) Microcomputer (b) Minicomputer (c) Mainframe (d) Supercomputer
Supercomputers are the most powerful computers, capable of performing trillions of calculations per second, making them ideal for complex simulations like weather forecasting and molecular modelling.
Q5. ROM is a type of: (a) Secondary memory (b) Primary memory (c) Output device (d) Input device
ROM (Read Only Memory) is a type of primary (main) memory. It is non-volatile — its contents are not lost when the power is switched off — and it stores essential boot-up instructions.
Q6. The full form of VLSI is: (a) Very Large Scale Integration (b) Very Low Scale Integration (c) Variable Large System Integration (d) Very Large System Instruction
VLSI (Very Large Scale Integration) is the technology of creating integrated circuits with thousands of transistors on a single chip, used in Fourth Generation computers.
Q7. Which of the following is an input device? (a) Monitor (b) Printer (c) Keyboard (d) Speaker
A keyboard sends data into the computer, making it an input device. Monitors, printers, and speakers are output devices.
Q8. EDSAC stands for: (a) Electronic Data Storage Automatic Calculator (b) Electronic Delay Storage Automatic Calculator (c) Electronic Delay System Automatic Computer (d) Electronic Data System Automatic Calculator
EDSAC was an early British computer that ran its first program in May 1949, designed by Maurice Wilkes.
II. Fill in the Blanks
1. The full form of ENIAC is Electronic Numerical Integrator and Calculator. 2. The ALU performs arithmetic and logical operations inside the CPU. 3. Second-generation computers used transistors instead of vacuum tubes. 4. The Control Unit coordinates and controls all activities of the computer. 5. RAM stands for Random Access Memory. 6. Supercomputers are the fastest and most powerful type of computers. 7. The basic operating cycle of a computer is Input – Process – Output (IPO cycle). 8. Vacuum tubes were used in first-generation computers. 9. The memory that retains data even when the power is switched off is ROM (Read Only Memory). 10. UNIVAC stands for Universal Automatic Computer. 11. The most commonly used type of computer today is the microcomputer (personal computer). 12. Computers are used in banking for ATM services and electronic fund transfers. 13. VLSI stands for Very Large Scale Integration. 14. The unit that presents processed results to the user is the Output Unit.
III. True or False (with corrections for false statements)
IV. Match the Following
| Column A | Column B |
|---|---|
| 1. First Generation | (d) Vacuum tubes |
| 2. Second Generation | (e) Transistors |
| 3. Third Generation | (a) Integrated Circuits |
| 4. Fourth Generation | (c) Microprocessors |
| 5. Fifth Generation | (f) Artificial Intelligence |
| 6. ENIAC | (b) First electronic computer |
| Column A | Column B |
|---|---|
| 1. Supercomputer | (e) Weather forecasting |
| 2. Mainframe | (d) Banking and insurance |
| 3. Minicomputer | (f) Departmental use |
| 4. Microcomputer | (a) Personal use |
| 5. ALU | (b) Arithmetic and logical operations |
| 6. Control Unit | (c) Coordinates all activities |
V. Answer Briefly (2-Mark Questions)
VI. Answer in Detail (5-Mark Questions)
Common Mistakes to Avoid
1. Confusing RAM and ROM characteristics — Remember: RAM is volatile (data lost on power off) and read-write; ROM is non-volatile and read-only.
2. Attributing transistors to the wrong generation — Transistors belong to the Second Generation, not the Third. The Third Generation used ICs.
3. Saying the Control Unit performs calculations — Only the ALU performs arithmetic and logical operations. The Control Unit only coordinates and directs.
4. Calling ENIAC the first computer without qualification — ENIAC is the first electronic general-purpose digital computer. Earlier mechanical devices existed (abacus, Pascaline, Babbage's Analytical Engine).
5. Mixing up computer types — Supercomputers (fastest, scientific) vs. Mainframes (many users, business) vs. Minicomputers (mid-range, departmental) vs. Microcomputers (personal use).
6. Forgetting to mention memory as a core component — A computer has FOUR main units: Input, CPU, Memory, and Output. Students often leave out memory.
7. Writing vague answers for applications — Be specific. Instead of "computers are used in hospitals," write "computers are used for CT scan image processing, patient record management, and telemedicine."
Exam Checklist
Before your exam, make sure you can:
- [ ] Define a computer and describe the IPO cycle
- [ ] List all four functional units and their roles
- [ ] Name the five generations with their technology, features, and examples
- [ ] Distinguish between RAM and ROM in a comparison table
- [ ] Differentiate between ALU and Control Unit functions
- [ ] Classify computers by size (super, mainframe, mini, micro)
- [ ] Explain at least three applications of computers in different fields
- [ ] Expand abbreviations: ENIAC, UNIVAC, EDSAC, VLSI, ULSI, CPU, ALU, RAM, ROM
- [ ] Correct false statements about computer generations and components
- [ ] Match generation numbers with their core technology