Input/Output — Set 5

Correct Answer: C. Output

• **Output** = the result of the computer's processing stage, delivered to the user through devices like monitors (visual), speakers (audio), or printers (physical), completing the Input-Process-Output cycle. • **Key fact** — Output can be temporary (soft copy visible on screen) or permanent (hard copy on paper); the nature of the output depends entirely on which output device is used. • Every user action ultimately produces some form of output — even saving a file generates a confirmation message — making output the essential feedback mechanism between the computer and the user. • 💡 Option A (Input) is wrong because it describes data entering the computer, not being delivered from it; Option B (Storage) is wrong because it refers to holding data on disks or memory, not presenting results to users; Option D (Processing) is wrong because it describes the CPU manipulating data internally, not delivering finished results externally.

Correct Answer: D. Input Device

• **Input Device** = any hardware tool that accepts data or commands from the user and converts them into electrical signals the CPU can process — keyboards, mice, scanners, and microphones are all primary examples. • **Key fact** — Without input devices, a computer is entirely passive; it cannot receive instructions, update data, or respond to user intent, making them the indispensable entry point of all computation. • Input devices span all human senses: keyboards and mice serve touch, microphones serve voice, cameras and scanners serve vision — enabling diverse and accessible interaction styles. • 💡 Option A (Output Device) is wrong because it presents data from the computer to the user — the reverse function; Option B (Storage) is wrong because it retains data between sessions rather than accepting new data from users; Option C (Memory) is wrong because RAM temporarily holds data the CPU is actively processing, which is not the same as entering new data.

Correct Answer: A. Magnetic Stripe Reader

• **Magnetic Stripe Reader** = a device that reads data encoded in the magnetic stripe on the back of credit and debit cards by detecting changes in magnetic polarity as the stripe passes across a read head. • **Key fact** — The magnetic stripe stores three tracks of data including the card number, expiry date, and service code; the reader decodes all of this in milliseconds to initiate a payment at a POS terminal. • Magnetic stripe technology is being replaced by EMV chip cards and contactless NFC payments, which generate unique per-transaction codes and are far harder to clone fraudulently. • 💡 Option B (Barcode Reader) is wrong because it uses reflected light to read printed bar patterns, not magnetic encoding on a card; Option C (OMR) is wrong because it detects pencil marks on paper forms, unrelated to card payment data; Option D (OCR) is wrong because it recognises printed or handwritten text characters optically, which has nothing to do with magnetic card stripes.

Correct Answer: C. Braille Embosser

• **Braille Embosser** = a specialised output device that punches raised dot patterns onto heavy paper following the Braille code, enabling visually impaired users to read computer-generated text through their sense of touch. • **Key fact** — A Braille embosser works alongside screen-reader software such as JAWS or NVDA, which converts on-screen text into Braille commands sent to the embosser, bridging digital content and tactile reading for blind users. • Each Braille cell consists of up to six raised dots in a 2x3 grid; the embosser uses a pin mechanism to press these patterns into thick, durable paper designed to withstand repeated handling. • 💡 Option A (Speakers) is wrong because they produce audio output for different accessibility needs and cannot be read by touch; Option B (Inkjet Printer) is wrong because it deposits flat ink that provides no tactile information; Option D (CRT Monitor) is wrong because it is a visual display device, providing no benefit to someone who cannot see.

Correct Answer: A. Joystick

• **Joystick** = an input device consisting of a pivoting vertical stick mounted on a base with one or more buttons, translating tilt direction and angle into movement signals used to control objects in games and simulations. • **Key fact** — Joysticks transmit analog signals proportional to the tilt angle, allowing fine-grained control of both direction and speed — unlike keyboard arrow keys, which signal only on or off with no gradation. • Beyond gaming, joysticks are widely used in aircraft simulators, industrial robotic arms, and medical imaging equipment where intuitive multi-directional control is essential. • 💡 Option B (Mouse) is wrong because it lies flat and slides across a surface rather than tilting on a pivot; Option C (Stylus) is wrong because it is a pen-shaped tool for drawing on touchscreens, not for directional movement control; Option D (Trackball) is wrong because it uses a rotatable sphere in a fixed housing, not a pivoting vertical stick.

Correct Answer: D. Inkjet

Inkjet printers are very common for home use because they can produce high-quality color photos. They use replaceable ink cartridges containing different colors. This technology is generally quieter than impact printers.

Correct Answer: A. Stylus

A stylus is a pen-shaped instrument used with touchscreens or graphics tablets for precision input. It allows for natural writing and drawing motions. Active styluses can even detect different levels of pressure.

Correct Answer: D. Monitor

The monitor is the primary visual interface between the user and the computer's operating system. It allows the user to see the cursor, icons, and windows. The screen size is usually measured diagonally in inches.

Correct Answer: D. Microphone

A microphone captures audio input, which can be interpreted by voice recognition software as commands. This technology is used for virtual assistants and dictation. It is a key component for accessibility and hands-free operation.

Correct Answer: D. Iris Scanner

An iris scanner is a biometric input device that uses mathematical pattern-recognition on images of the iris. It is considered one of the most accurate security measures available. It is often used in high-security government and corporate facilities.