Computing Science - National 5 FINAL EXAMS [100% PASS]

Computing Science - National 5 FINAL EXAMS [100% PASS] Positive Numbers in Binary *Ans* 4 2 1 0 1 1 0 0 0 1 1 This shows the number 99 in binary. A one is 'on' or 'used' and a 0 is 'off' or 'not used' The numbers that are on in this example are: 64 + 32 + 2 + 1 = 99 Real Numbers *Ans* Real numbers allow the computer to store decimal values. The Mantissa dictates the precision of numbers and the Exponent dictates the range Mantissa *Ans* The number of bits allocated to the Mantissa dictates the precision of a real number. More bits to the Mantissa leads to greater precision. Less bit leads to less precision. Exponent *Ans* The number of bits allocated to the Exponent dictates the range of a real number. More bits to the Exponent leads to greater range. Less bit leads to less range. (Extended) ASCII *Ans* Extended ASCII is one way to represent a character set. Extended ASCII code uses 8 bits to represent a character meaning that you can represent up to 256 different characters. Printable Characters(ASCII) *Ans* Printable characters are those that you will be able to see on screen. They have an 8 bit ASCII code. Examples are: A, s, !, @ Control Characters (ASCII) *Ans* Control Characters are those that do not appear on screen but that carry out a task. They have an 8 bit ASCII code. Examples are: Shift, Delete, Backspace, F2, Ctrl Bit Mapped Graphics *Ans* Bit Mapped graphics are made up of a 2D array of pixels. Every single pixel is saved. JPEG, PNG and GIF are bit mapped graphic formats. Bit Depth(Colour Depth for Graphics) *Ans* Every pixel is stored as a binary code. Bit depth is the number of bits used to store each pixel. A bit depth of 8 bits allows the pixel to be one of 256 colours, a bit depth of 16 bits allows for 65,536 colours and a bit depth of 24bits allows for 16, 777, 216 colours. The higher the bit depth the larger the file size but the more colour available. Resolution *Ans* Resolution is the total number of pixels in an image. E.g. A resolution of 800 x 600 would create 480,000 pixels Vector Graphics *Ans* Vector graphics are NOT stored as individual pixels. Instead a description of attributes is used to create an object/shape. E.g. for a circle the attributes might be: