💻 COMPUTER HARDWARE – Complete Notes
(Home Academy | Exam-Oriented for JKSSB, SSC, Bank, UGC NET)
🔹 1. Meaning of Hardware
Hardware refers to the physical components of a computer system that you can touch and see. Hardware works together with software to perform computing tasks.
Examples: CPU, Monitor, Keyboard, Mouse, Printer, Hard Disk.
🔹 2. Types of Hardware
2.1 Input Devices
Devices used to enter data and commands into a computer.
Examples: Keyboard, Mouse, Scanner, Microphone, Joystick.
2.2 Output Devices
Devices used to receive and display data from a computer.
Examples: Monitor, Printer, Speaker, Projector.
2.3 Storage Devices
Devices used to store data permanently or temporarily.
Examples: Hard Disk Drive (HDD), Solid State Drive (SSD), Pen Drive, CD/DVD, Memory Cards.
2.4 Processing Devices
Devices that process data and execute instructions.
Examples: CPU (Central Processing Unit), GPU (Graphics Processing Unit).
2.5 Communication Devices
Hardware used to transmit data between computers.
Examples: Modem, Network Interface Card (NIC), Router, Hub, Switch.
🔹 3. Main Components of Computer Hardware
CPU (Central Processing Unit) – The brain of the computer; executes instructions.
Motherboard – Main circuit board connecting all components.
RAM (Random Access Memory) – Temporary memory used to store data and programs in use.
ROM (Read Only Memory) – Permanent memory storing system instructions.
Power Supply Unit (PSU) – Provides electrical power to all components.
Input/Output Ports – Connect peripherals like USB devices, printers, and monitors.
GPU (Graphics Processing Unit) – Handles graphics rendering and processing for images/videos.
🔹 4. Types of Storage Hardware
| Storage Type | Volatility | Examples |
|---|---|---|
| Primary Storage | Volatile | RAM |
| Secondary Storage | Non-volatile | HDD, SSD |
| Tertiary Storage | Non-volatile, offline | Magnetic tapes, Optical Discs |
| Cloud Storage | Non-physical | Google Drive, OneDrive |
🔹 5. Peripheral Devices
Peripheral devices are hardware devices connected to the main computer to extend functionality.
Input peripherals: Keyboard, Mouse, Scanner.
Output peripherals: Printer, Speaker, Projector.
Combined I/O peripherals: Touchscreen, Modem.
🔹 6. Hardware vs Software
| Feature | Hardware | Software |
|---|---|---|
| Tangibility | Physical | Intangible |
| Function | Performs tasks | Gives instructions |
| Examples | CPU, Monitor | Operating System, Applications |
| Lifetime | Can wear out | Can be updated |
🔹 7. Key Points for Exams
Hardware = Physical components of a computer.
CPU = Brain, RAM = Working memory, ROM = Permanent instructions.
Input devices provide data; Output devices display results.
Storage hardware = Primary, Secondary, Tertiary, Cloud.
Peripherals extend computer functionality.
📘 MCQs – Computer Hardware
1. Which of the following is hardware?
A) Windows OS
B) Microsoft Word
C) Monitor
D) Antivirus
✅ Answer: C) Monitor
2. CPU stands for:
A) Central Processing Unit
B) Computer Processing Unit
C) Central Program Unit
D) Control Processing Unit
✅ Answer: A) Central Processing Unit
3. RAM is:
A) Permanent memory
B) Volatile memory
C) Storage device
D) Output device
✅ Answer: B) Volatile memory
4. Which of the following is an output device?
A) Keyboard
B) Mouse
C) Printer
D) Scanner
✅ Answer: C) Printer
5. Motherboard is:
A) Storage device
B) Main circuit board
C) Output device
D) Input device
✅ Answer: B) Main circuit board
6. Which of the following is a secondary storage device?
A) RAM
B) SSD
C) ROM
D) CPU
✅ Answer: B) SSD
7. Touchscreen is an example of:
A) Input device
B) Output device
C) Both input and output device
D) Storage device
✅ Answer: C) Both input and output device
8. GPU is mainly used for:
A) Data storage
B) Audio processing
C) Graphics processing
D) Keyboard input
✅ Answer: C) Graphics processing
9. Peripheral devices are:
A) Main components of CPU
B) Connected externally to extend functionality
C) Always internal hardware
D) Software programs
✅ Answer: B) Connected externally to extend functionality
10. Which hardware is considered volatile memory?
A) SSD
B) HDD
C) RAM
D) ROM
✅ Answer: C)