Input devices questions and answers
Q1. Why is a ‘qwerty’ keyboard called a ‘qwerty’ keyboard?
A1. The row of keys on the actual keyboard spell the word qwerty.
Q2. Who might use a graphics tablet and what might they use it for?
A2. E.g. an artist, engineer, graphical designer to draw and edit pictures.
Q3. How does a scanner work when scanning a picture?
A3. Place the picture on the scanner, cover, select resolution and other settings, a light is shone over the picture and reflected back, the reflections are turned into pixels, all of the pixels together make up a bitmap, the software can then be used to compress the file into a JPG or GIF, for example, and then finally, editing software can be used to edit the picture, make corrections etc.
Q4. Explain how a video capture card works.
A4. A video capture card is a piece of hardware that is plugged into an expansion slot inside the computer. A user then attaches a video camera or TV, for example, to the video card. When the video or TV is played through the card, the analogue signals that make up the moving picture from these devices are converted into digital images, frame-by-frame and stored.
Q5. What is a 'peripheral'?
A5. Any device you can connect to the computer's CPU usually via a port is called a peripheral.
Q6. What is a 'port' used for?
A6. This is a place that you connect a peripheral into a computer.
Q7. Describe what a digital signal is.
A7. A digital signal is one that is made up of binary signals (ones and zeros).
Q8. Describe what an analogue signal is.
A8. An analogue signal is one that is made up of an infinite number of possible values.
Q9. What is a bit map?
A9. A bit map is a picture file where the details of every pixel are stored.
Q10. Why are picture files turned into e.g. GIF or JPG formats?
A10. GIF and JPGs are codecs that 'squash' bit map files by removing the unnecessary parts. The resulting files are much smaller.