AQA A LEVEL COMPUTER SCIENCE PAPER 2

AQA A LEVEL COMPUTER SCIENCE PAPER 2 Answer all questions. 0 1 . 1 Shade one lozenge to indicate which of the unsigned numbers listed in Table 1 has the largest value. Table 1 Number base Number Largest value (shade one) Binary Hexadecimal 30A Decimal 396 [1 mark] Questions 01.2 and 01.3 use a normalised floating point representation with a 7-bit mantissa and a 5-bit exponent, both stored using two’s complement. The following is a floating point representation of a number: 0 1 . 2 Calculate the decimal equivalent of the number. You must show your working. [2 marks] Answer 0 1 0 1 1 0 0 1 1 1 0 1 Mantissa Exponent 3 *03* Turn over ► IB/M/Jun18/7517/2 Do not write outside the box 6 0 1 . 3 Write the normalised floating point representation of the decimal value -608 in the boxes below. You must show your working. [3 marks] Answer Mantissa Exponent Turn over for the next question 4 *04* IB/M/Jun18/7517/2 Do not write outside the box 0 2 Figure 1 shows an image composed of four objects, represented digitally as a vector graphic. Figure 2 shows the same image, represented digitally as a bitmap graphic. The bitmap graphic has an image size of 50 x 50 pixels. Each image uses four colours: white, black, yellow and blue. Figure 1 Figure 2 0 2 . 1 Describe how a vector graphic is represented. Include an explanation of how the black rectangle in Figure 1 would be represented in your description. [3 marks] 5