Page 69 - Computer Science Class 11 With Functions
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Case Based Questions


               1.  Nirankar has just learnt about the hexadecimal number system. With his previous knowledge of the decimal number
                  system, he knows how to compute the value using the place value and face value of symbols given in the number. He has
                  computed the decimal value of the hexadecimal number system, (D20.B1)  as given below:
                                                                              16
                  (D20.B1) 16
                                1
                                       2
                        0
                                               -1
                  = D × 16  + 2 × 16  + 0 × 16  + B × 16  + 1 × 16 -2
                  = 13 × 1 + 2 × 16 + 0 × 256 + 11 × 0.0625 + 1 × 0.0039
                  = 13 + 32 + 0 + 0.6875 + 0.0039
                  = (45.6914) 2
                  Is the computation correct? If not, give the correct computation.
               2.  Sheikh just came to know that hexadecimal numbers are used to represent colors in digital form. He knows that red, green,
                  and blue are the three primary colors, referred to as RGB. He has formed a table that gives the name of the color along with
                  its decimal value and hexadecimal value. Help him complete the table.

                                   Name of Colour      Decimal Value       Hexadecimal Value

                                       Yellow                                  (FF, FF, 00)
                                                        (256, 0, 0)
                                        Blue            (0, 0, 255)
                                        Black
                                       Green                                  (00, FF, 00)

               3.  Saptarishi is learning about ASCII, which is a 7-bit encoding scheme to codify 128 different characters. He now wants to
                  encode the following words using ASCII and thereafter write their binary equivalent. Help him complete the task. You may
                  refer to ASCII table given in the chapter.

                                  Word            ASCII Code                Binary equivalent
                                  BOT              66  79  84
                                   KEY             75  68  89
                                 NUMber                            1001110  1010101  1001101  1100010
                                                                           1100101  1110010
                                 Yes-NO














              Multiple Choice Questions
              1. (a)     2. (d)      3. (a)     4. (c)     5. (c)      6. (a)     7. (b)     8. (b)
              9. (a)     10. (c)
              True or False
              1. (T)     2. (F)      3. (T)     4. (F)     5. (T)      6. (F)
              Fill in the blanks
              1. number            2. three              3. seven              4. 0,9               5. 2



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