Computer Hardware and Components

The CPU (Central Processing Unit) is the 'brain' of the computer. It has THREE parts: (1) ALU (Arithmetic Logic Unit) — performs all arithmetic (+, -, ×, ÷) and logical (compare, AND/OR) operations; (2) CU (Control Unit) — directs and coordinates all operations, acts like a traffic police but does NOT process data; (3) Registers / MU — small high-speed storage inside CPU. Memory hook: 'A Control Register' = ALU + CU + Registers. The CPU is also called the microprocessor in PCs. Clock speed is measured in Hertz (GHz). Examples of input→process→output flow always pass through the CPU. The motherboard is the main circuit board that connects CPU, memory, and all components.

INPUT devices send data INTO the computer: keyboard, mouse, scanner, joystick, light pen, microphone, webcam, barcode reader, OMR, OCR, MICR (used on cheques!). OUTPUT devices send data OUT to the user: monitor, printer, speaker, plotter, projector. Trick devices: a Touchscreen and a Modem are BOTH input and output. A printer is output; a scanner is input. MICR (Magnetic Ink Character Recognition) is heavily tested — it reads the special magnetic numbers at the bottom of bank cheques. Memory aid: if a human feeds it → input; if it shows/gives a result → output. Monitors are measured diagonally; resolution is in pixels.

When a clerk enters a cheque: the MICR reader (INPUT) reads the magnetic code → data travels to CPU via the motherboard → ALU verifies the amount, CU controls the sequence → result stored temporarily in RAM (primary memory) → final record saved to hard disk (secondary storage) → a receipt is produced on a printer (OUTPUT) and shown on the monitor (OUTPUT). Note the device categories: MICR = input, printer/monitor = output, RAM = volatile primary memory, hard disk = non-volatile secondary memory. Ports connect devices: USB (universal), HDMI/VGA (display), Ethernet (network). This single chain answers many 'which is input/output/storage' questions in one go.

Cover the answer, recall, then check. 12 cards on hardware, CPU parts and I/O devices for IBPS Clerk.

Q1. What are the two main functional units of the CPU?
A1. ALU (Arithmetic Logic Unit) and CU (Control Unit); registers store data temporarily.

Q2. What does the ALU do vs the Control Unit?
A2. ALU performs arithmetic and logical operations; CU directs/coordinates all operations (fetch-decode-execute).

Q3. Which board is the main circuit board of a computer?
A3. The Motherboard (mainboard), which holds the CPU, RAM, and connects all components.

Q4. Classify these: keyboard, mouse, scanner, joystick, light pen.
A4. All are INPUT devices.

Q5. Classify these: monitor, printer, speaker, plotter, projector.
A5. All are OUTPUT devices.

Q6. Impact vs non-impact printers — give examples of each.
A6. Impact: Dot-matrix, Daisy-wheel, Line printer. Non-impact: Inkjet, Laser, Thermal.

Q7. What does MICR stand for and where is it used?
A7. Magnetic Ink Character Recognition — reads the code line on bank cheques.

Q8. Differentiate OMR and OCR.
A8. OMR (Optical Mark Reader) detects marks like exam bubbles; OCR (Optical Character Recognition) reads printed/handwritten text.

Q9. What does SMPS supply in a computer?
A9. SMPS (Switched Mode Power Supply) converts AC to regulated DC power for components.

Q10. Name the three types of system bus.
A10. Data bus, Address bus, and Control bus.

Q11. Which device converts hard copy (paper) into a digital image?
A11. A Scanner.

Q12. Is a touchscreen an input device, output device, or both?
A12. Both — it displays output and accepts touch input.