Page 85 - Computer science 868 Class 12
P. 85

MIND DRILL




                     Solved Questions


                 A.  Tick ( ) the correct option:
                    1.  (A NAND A) NAND (B NAND B) is equivalent to ………………… .
                       a.  OR                                          b.  NAND
                       c.  NOR                                         d.  AND
                    2.  The Boolean expression for a two-variable XOR gate is ………………… .
                       a.  A'.B'+A.B                                   b.  A'.B+A.B'
                       c.  A'+B'                                       d.  A'.B'

                                              A
                    3.  Which gate is represented by   B    out ?
                       a.  OR                                          b.  NOR
                       c.  XOR                                         d.  XNOR
                    4.  Which of the following are known as universal gates?
                       a.  NAND and NOR                                b.  AND and OR
                       c.  XOR and OR                                  d.  XNOR and OR
                    5.  (A NOR A) NOR (B NOR B) is equivalent to ………………… .
                       a.  OR                                          b.  NAND
                       c.  NOR                                         d.  AND
                    6.   The NOR gate output will be high if the two inputs are ………………… .
                       a.  00                                          b.  01
                       c.  10                                          d.  11

                    7.  How many AND gates are required to realise Y = A.B.C+D.E+F?
                       a.  4                                           b.  5
                       c.  3                                           d.  2
                    8.  A full adder logic circuit will have ………………… .
                       a.  two inputs and one output                   b.  three inputs and three outputs
                       c.  three inputs and two outputs                d.  two inputs and two outputs
                    9.  Which of the following is true for XOR gate?
                       a.  It results in 1 when all inputs are 1       b.  It results in 1 for odd number of 1 as inputs
                       c.  It results in 1 for even  number of 1 as inputs   d.  It results in 1 for any input as 1
                   10.  Which of the  following are fundamental gates?
                       a.  NAND, NOR                                   b.  XOR, XNOR
                       c.  AND, OR                                     d.  NOT, NOR

                   Answers
                     1.  a     2.  b     3.  c     4.  a    5.  d     6.  a     7.  c     8.  c     9.  b     10.  c


                 B.  Fill in the blanks:
                    1.  The boolean expression of a two-variable NAND gate represented by variables A and B is ………………… .
                    2.  The gate produced by inverting the XOR gate is ………………… .
                    3.  ………………… NAND gates in series are equivalent to AND gate.




                                                                                                                        83
                                                                                                   Computer Hardware    83
   80   81   82   83   84   85   86   87   88   89   90