2 Input and output devices (3)
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Information Communication Technology ICT
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1.
Explain how a scanner and a camera function as input devices. Compare and contrast their strengths and weaknesses in terms of image quality, ease of use, and storage requirements. Provide examples of situations where each device would be the most appropriate choice.
Answer:
Scanner: A scanner captures an image of a physical document or object by shining a light through it and using sensors to convert the light into digital data. It essentially creates a digital representation of the physical world. Scanners are typically connected to a computer via USB.
Camera: A camera captures an image by focusing light onto a sensor (CCD or CMOS). The sensor converts the light into electrical signals, which are then processed to create a digital image. Cameras can be integrated into devices like smartphones, or they can be standalone units.
Comparison:
Image Quality: Cameras generally produce higher quality images than scanners, especially in terms of color accuracy and detail. Scanners can sometimes struggle with curved or textured surfaces.
Ease of Use: Cameras are generally easier to use, requiring minimal setup. Scanners may require software calibration and adjustments to achieve optimal results.
Storage Requirements: Scanned images can be large files, especially at high resolutions. Camera images also require storage, but modern cameras often have built-in storage or can easily transfer to external storage devices.
Appropriate Choices:
- Scanner: Best for digitizing documents, artwork, or photographs. Suitable for archiving physical materials and creating searchable PDFs.
- Camera: Best for capturing images and videos in real-time. Suitable for photography, videography, surveillance, and capturing images for social media.
2.
Describe the characteristics, uses, advantages, and disadvantages of at least three different output devices. Your answer should consider the suitability of each device for different tasks.
Answer:
Output devices are essential for presenting processed information to the user. Different devices have varying characteristics, making them suitable for specific applications. Here's a comparison of three output devices:
- Monitor:
- Characteristics: Displays visual information using pixels. Resolution (e.g., 1920x1080) determines image clarity. Screen size impacts viewing comfort.
- Uses: General computing, graphic design, video editing, gaming, presentations.
- Advantages: Clear visual display, versatile, relatively inexpensive, readily available.
- Disadvantages: Can cause eye strain with prolonged use, susceptible to damage (e.g., screen cracking), limited portability (unless portable monitors).
- Laser Printer:
- Characteristics: Uses a laser beam to create an image on a drum, which then transfers toner to paper. Produces high-quality text and graphics.
- Uses: Office documents, reports, presentations, high-quality photo printing.
- Advantages: Fast printing speeds, sharp text quality, suitable for high-volume printing, durable prints.
- Disadvantages: More expensive than inkjet printers, higher running costs (toner cartridges), larger footprint.
- 3D Printer:
- Characteristics: Creates three-dimensional objects from a digital design by layering material (plastic, metal, etc.). Various technologies exist (e.g., FDM, SLA).
- Uses: Prototyping, manufacturing custom parts, creating models, medical applications (e.g., prosthetics).
- Advantages: Rapid prototyping, custom design capabilities, can create complex geometries, reduces waste compared to traditional manufacturing.
- Disadvantages: Can be slow, expensive, requires specialized materials, complex to operate and maintain.
The suitability of each device depends on the task. A monitor is ideal for general use and visual tasks. A laser printer is best for producing high-quality documents. A 3D printer is suitable for prototyping and creating physical objects.
3.
Compare and contrast the use of a barcode reader and an RFID reader in data entry. Discuss the situations where each type of reader would be most appropriate, highlighting their respective strengths and weaknesses.
Both barcode and RFID readers are used for automated data entry, but they operate on different principles and have distinct characteristics. Barcode readers require a direct line of sight to the barcode and rely on the pattern of black and white lines to be decoded. They are typically less expensive and suitable for applications where items are readily visible and barcodes are easily printed. RFID readers use radio waves to communicate with RFID tags, which can be read from a greater distance without a direct line of sight. RFID tags can store more data than barcodes and are useful for tracking items in warehouses, inventory management, and access control.
Here's a comparison table:
Feature | Barcode Reader | RFID Reader |
Reading Distance | Short - Requires direct line of sight | Long - Can read from a distance |
Cost | Lower | Higher |
Data Capacity | Limited | Larger |
Line of Sight | Required | Not required |
Typical Uses | Retail point of sale, inventory scanning | Supply chain management, access control, asset tracking |
Barcode readers are most appropriate for applications where items are individually scanned at a point of sale, such as in retail stores. RFID readers are better suited for applications where tracking items over a larger area is necessary, such as in warehouses or for inventory management. Barcode readers are generally more reliable in harsh environments, while RFID readers are less susceptible to damage due to their wireless nature. However, RFID readers can be more vulnerable to signal interference.