Computer Fundamentals: Generations, Hardware and Devices
Computer Fundamentals: Generations, Hardware and Devices
Computer awareness questions in NTPC test the basics every office worker needs: how computers developed, what the CPU and its parts do, which devices are input and which are output, and the full forms of common abbreviations. Recent NTPC Graduate papers (March 2026) asked the role of the control unit and the full form of BIOS.
1. Generations and History
| Generation | Technology | Example |
|---|---|---|
| First (1940s-1956) | Vacuum tubes | ENIAC, UNIVAC |
| Second (1956-1963) | Transistors | IBM 1401 |
| Third (1964-1971) | Integrated circuits (ICs) | IBM 360 |
| Fourth (1971 onward) | Microprocessors (VLSI) | Personal computers |
| Fifth (present and future) | Artificial intelligence, parallel processing | AI systems |
| Fact | Detail |
|---|---|
| Father of the computer | Charles Babbage (Analytical Engine) |
| First programmer | Ada Lovelace |
| First Indian supercomputer | PARAM 8000 (1991), C-DAC, led by Vijay Bhatkar |
| First microprocessor | Intel 4004 (1971) |
2. CPU and Hardware
| Part | Role |
|---|---|
| CPU | Brain of the computer; ALU + control unit + registers |
| ALU | Arithmetic and logical operations |
| Control unit (CU) | Directs and coordinates all operations; fetches and decodes instructions |
| Registers | Fastest storage inside the CPU |
| Motherboard | Main circuit board connecting all parts |
| SMPS | Supplies power to components |
| BIOS | Basic Input/Output System; starts the computer (booting) |
| Clock speed | Measured in hertz (GHz) |
3. Input and Output Devices
| Type | Devices |
|---|---|
| Input | Keyboard, mouse, scanner, microphone, joystick, light pen, webcam, barcode reader |
| Output | Monitor, printer, speaker, plotter, projector |
| Both input and output | Touchscreen, modem, headset with microphone |
| OCR | Optical Character Recognition: reads printed text |
| MICR | Magnetic Ink Character Recognition: reads cheque numbers in banks |
| OMR | Optical Mark Recognition: reads answer sheets |
| Impact printer | Dot matrix |
| Non-impact printers | Laser, inkjet |
Common full forms: CPU Central Processing Unit; ALU Arithmetic Logic Unit; USB Universal Serial Bus; GUI Graphical User Interface; PDF Portable Document Format; VDU Visual Display Unit
✗ The ALU controls and coordinates all parts of the computer | ✓ The control unit coordinates; the ALU only does arithmetic and logical work
✗ A scanner is an output device | ✓ A scanner is an input device; a printer is an output device
हिंदी नोट: पहली पीढ़ी में निर्वात नलिकाएँ, दूसरी में ट्रांज़िस्टर, तीसरी में IC और चौथी में माइक्रोप्रोसेसर उपयोग हुए। नियंत्रण इकाई (CU) कंप्यूटर के सभी कार्यों का समन्वय करती है। BIOS का पूरा नाम बेसिक इनपुट/आउटपुट सिस्टम है। चार्ल्स बैबेज कंप्यूटर के जनक हैं।
Exam Pointer: Verified NTPC patterns: the role of the control unit (March 2026 Graduate CBT-1), classifying input and output devices (August 2025 UG CBT-1) and the full form of BIOS (March 2026 Graduate CBT-1). Generation questions are tagged syllabus-based.
Pariksha Pattern: Every Way NTPC Asks This Topic
Pattern 1: CPU, ALU and control unit
[PYQ: NTPC Graduate CBT-1 19-Mar-2026 Shift-2]
EXAM LEVEL
Q. Which part of the CPU performs addition and comparison?
The Arithmetic Logic Unit (ALU).
Answer: ALU
EXAMATLAS LEVEL
Q. Name the three main parts of a CPU and say which one fetches and decodes instructions. Which storage inside the CPU is the fastest?
The CPU has the ALU, the control unit and registers. The control unit fetches and decodes instructions and coordinates the other parts. Registers are the fastest storage.
Answer: ALU, CU, registers; control unit; registers
Pattern 2: Input and output devices
[PYQ: NTPC UG CBT-1 28-Aug-2025 Shift-3]
EXAM LEVEL
Q. Is a plotter an input or an output device?
An output device; it draws large graphics such as maps and designs.
Answer: Output
EXAMATLAS LEVEL
Q. Classify: light pen, projector, touchscreen, barcode reader, speaker. Which device do banks use to read the numbers printed on cheques?
Light pen and barcode reader are input; projector and speaker are output; touchscreen is both. Banks use MICR to read cheque numbers.
Answer: Input: light pen, barcode reader; output: projector, speaker; both: touchscreen; MICR
Pattern 3: Abbreviations and firsts
[PYQ: NTPC Graduate CBT-1 18-Mar-2026 Shift-1]
EXAM LEVEL
Q. What is the full form of USB?
Universal Serial Bus.
Answer: Universal Serial Bus
EXAMATLAS LEVEL
Q. Give the full forms of OMR and GUI, and name the first Indian supercomputer and the body that built it.
OMR is Optical Mark Recognition and GUI is Graphical User Interface. PARAM 8000 (1991) was built by C-DAC.
Answer: Optical Mark Recognition, Graphical User Interface; PARAM 8000, C-DAC
Pattern 4: Generations of computers
[Pattern: syllabus-based, PYQ-style]
EXAM LEVEL
Q. Which generation of computers used vacuum tubes?
The first generation, such as ENIAC.
Answer: First
EXAMATLAS LEVEL
Q. Arrange in order of generation: integrated circuits, transistors, microprocessors, vacuum tubes. Who is called the father of the computer?
Vacuum tubes (first), transistors (second), integrated circuits (third), microprocessors (fourth). Charles Babbage is called the father of the computer.
Answer: Vacuum tubes, transistors, ICs, microprocessors; Charles Babbage
60-Second Revision
- Generations: vacuum tube, transistor, IC, microprocessor, AI.
- CPU = ALU + CU + registers; CU coordinates; registers fastest.
- Input: keyboard, scanner, mic; output: monitor, printer, plotter; both: touchscreen.
- BIOS, USB, OCR, MICR (cheques), OMR (answer sheets); Babbage; PARAM 8000.