COMPSCI

What is meant with Input Device ?

An input device allows users to send data to a computer for processing.

Mention 3 Input Device at Cashier system ?

Barcode Scanner, Keyboard, QR Code Reader

Explain what its meant with Barcode and how its works  ?

A barcode is a machine-readable representation of data that consists of a series of parallel lines (1D) or patterns (2D). It is commonly used to store information about a product, such as its price, name, or identification number.

How it Works: Scanning: A barcode scanner emits a light beam onto the barcode. Reflection: The light is reflected back differently by the black bars and white spaces Decoding: The scanner interprets the reflected light as binary data (1s and 0s)

Output: The decoded data is sent to the cashier's system, displaying the product information.

Mention 3 Advantages using Barcode system ?

Increases Accuracy: Reduces human errors during data entry. Speeds Up Operations: Processes transactions quickly. Improves Inventory Management: Tracks stock levels efficiently.

Explain how Barcode scanner works ?

Scans Light: Emits light onto the barcode. Reads Reflection: Captures reflected light from black bars and white spaces. Decodes Data: Converts the pattern into readable data for the system

Explain what its meant with QR code and how its works ?

A QR code is a two-dimensional barcode storing larger amounts of data, such as URLs or text. Scanning: A camera or scanner captures the QR code. Decoding: Software converts the image into data for use.

Explain how Digital Camera works ?

Captures Light: Light passes through the lens to a sensor (CCD or CMOS). Converts to Electrical Signals: The sensor converts light into digital signals. Processes Image: The camera's processor refines the data into a photo.

Mention 4 task that can do by camera automatically ?

Autofocus, Adjust exposure, Detect faces, Stabilize images

What its meant with CCD ?

A CCD (Charge-Coupled Device) is an image sensor in cameras that captures light and converts it into electrical signals.

What its meant with ADC ?

An ADC (Analog-to-Digital Converter) converts analog signals (e.g., light intensity) into digital data.

Explain how keyboard works ?

Key Press: A key is pressed, completing a circuit. Signal Sent: An electrical signal is sent to the processor. Interpretation: The processor decodes the signal into a corresponding character.

What its meant with Repetetive Strain Injuries ( RSI )

RSI refers to injuries caused by repetitive motions, leading to pain in muscles or tendons (e.g., from typing or mouse use).

Explain How microphones works ?

Captures Sound Waves: A diaphragm vibrates when sound waves hit it. Converts to Electrical Signals: The vibrations are converted into electrical signals. Processes Audio: Signals are amplified or processed for output.

Explain how Optical Mouse works ?

 LED or Laser Emits Light: Shines light on the surface. Captures Movement: A sensor detects surface changes as the mouse moves. Translates Motion: The signals are converted into cursor movements.

Explain the stages how 2D scanner works ?

Illumination: The scanner illuminates the document with a light source. Reflection: Light reflects back to the scanner. Capture: Sensors (CCD/CMOS) record the reflected light. Processing: Data is converted into a digital image.

What its meant with 3D Scanner ?

A 3D scanner is a device that captures the shape and geometry of a physical object, creating a digital 3D model using lasers, light, or X-rays.

What its meant with 2D Scanner ?

A 2D scanner captures flat images of documents or photographs, converting them into a digital format.

Explain application 2D Scanner at airport ?

Application of 2D Scanner at Airports

Used for scanning travel documents like passports, tickets, and boarding passes to verify passenger information.

What its meant with touchscreen ?

A touchscreen is an input device that allows users to interact with a display by touching it directly with fingers or a stylus.

Explain how Capacitive Touch screen works ?

Conductive Layer: The screen is coated with a conductive material. Touch Detection: When touched, the screen detects changes in electrical charge. Signal Processing: The device calculates the touch location using sensors.

Explain how Infrared Touchscreen works ?

Grid of Infrared Beams: Emitters and sensors form an invisible grid on the screen. Touch Detection: A touch disrupts the beams. Signal Processing: The system calculates the touch point based on the interruption.

Explain how resistive touchscreen works ?

Two Flexible Layers: The screen has two conductive layers separated by a gap. Touch Detection: Pressing the screen makes the layers touch, completing a circuit. Signal Processing: The device calculates the touch location.

Mention 3 advantages capacitive touchscreen ?

1. High durability and scratch resistance.

2. Supports multi-touch gestures.

3. Excellent clarity and brightness.

Mention 3 advantages Infrared touchscreen ?

1. Works with any input (fingers, gloves, or stylus).

2. High accuracy and response time.

3. Durable and long-lasting.

Mention 2 advantages resistive touchscreen ?

1. Works with any input type, including gloves or stylus.

2. Cost-effective and widely available.

Explain what its meant with actuator and how its works ?

An actuator is a device that converts energy (electrical, hydraulic, or pneumatic) into mechanical motion. It works by receiving a control signal and moving or adjusting components accordingly.

Explain how DLP ( Digital Light Projectors ) works ?

Light Source: Emits light that passes through a color wheel. DMD Chip: A chip with thousands of tiny mirrors reflects light to create the image. Projection: The image is projected onto a screen.

Explain how LCD projectors works ?

1. Explain how LCD projectors works ?

Light Source: Emits light that passes through three LCD panels (red, green, and blue). Image Formation: Panels modulate light to form the image. Projection: Combines the colors and projects the image onto a screen.

Mention 3 advantages using DLP Projector ?

1. Compact and lightweight design.

2. High contrast ratios for deeper blacks.

3. Smooth video playback with minimal motion blur.

Mention 3 advantages using LCD Projector ?

1.Bright and vibrant images, even in well-lit environments.

2. Lower power consumption.

3. Sharper and more detailed image quality.

Mention 2 advantages using DLP Projector ?

1. Compact Size: Lightweight and portable.

2. High Contrast: Produces deep blacks and vivid colors.

Mention 2 advantages using LCD Projector ?

1. Bright Images: Suitable for well-lit rooms.

2. Sharp Image Quality: Ideal for detailed visuals.

Mention and explain 4 component of Inkjet printers ?

1. Print Head: Contains nozzles that spray ink onto paper.

2. Ink Cartridges: Store the ink used for printing.

3. Stepper Motor: Moves the print head across the page.

4. Paper Feed Mechanism: Feeds paper into the printer.

Explain what its meant with Thermal bubble ?

Thermal bubble technology uses heat to create a bubble inside the ink chamber, which forces ink through the nozzles and onto the paper.

Explain what its meant with Piezoelectric ?

Piezoelectric technology uses a crystal that vibrates when electrically charged, pushing precise amounts of ink through the nozzles.

Explain how inkjet printer works ?

Ink Ejection: Ink is sprayed through tiny nozzles onto the paper. Controlled by Software: The print head moves horizontally while the paper moves vertically. Image Formation: Dots of ink combine to form text or images.

Explain how Laser printer works ?

Laser Beam: A laser creates an electrostatic image on a rotating drum. Toner Application: The drum attracts toner powder to the charged areas. Fusing: The toner is melted onto the paper by heat and pressure.

Explain 2 differences between laser printer and inkjet printer ?

1. Speed: Laser printers are faster than inkjet printers.

2. Cost: Inkjet printers are cheaper to buy but have higher running costs.

Explai how 3D printer works ?

Model Design: A 3D model is created using software. Layer-by-Layer Printing: The printer deposits material (e.g., plastic) layer by layer to build the object. Solidification: Layers harden to form the final product.

Explain what its meant with Binder 3D Printing ?

A method where a liquid binding agent is applied to powdered material to build the object layer by layer.

Explain what its meant with Direct 3D Printing ?

A method that uses material extrusion, such as melted plastic, to create objects directly layer by layer.

How 3D printers used in industry ?

Prototyping: Rapidly creating product prototypes. Custom Manufacturing: Producing custom parts and tools. Medical: Creating prosthetics and implants.

Explain how LCD screens works ?

Backlight: Light passes through liquid crystal layers. Pixel Control: Electric currents adjust the crystals to control light. Image Display: Colored filters form the final image.

Explain how LED screens works ?

LEDs as Light Source: LEDs provide light directly or through a backlight. Pixel Illumination: Each pixel is lit individually for brightness and color. Image Formation: Combines lights to display visuals.

Mention 3 advantages using OLEDS

1. Thin and lightweight screens.

2. High contrast with deep blacks.

3. Flexible and durable designs.

Mention 3 advantages using LED ?

1. Energy-efficient.

2. Long lifespan.

3. Brighter displays.

Explain how loud speakers works ?

Electric Signal: Audio signals are sent to the speaker. Coil Vibration: A voice coil vibrates in response to the signal. Sound Production: Vibrations move a diaphragm, producing sound waves