Question

Four NOR gates are connected as shown in figure. The truth table for the given figure is :

• A.

  A	B	Y
  0	0	1
  0	1	0
  1	0	1
  1	1	0

• B.

  A	B	Y
  0	0	0
  0	1	1
  1	0	1
  1	1	0

• C.

  A	B	Y
  0	0	0
  0	1	1
  1	0	0
  1	1	1

• D.

  A	B	Y
  0	0	1
  0	1	0
  1	0	0
  1	1	1

Answer 1

Answer: (D)

$y=\overline{\overline{A+\overline{A+B})}+\overline{B+\overline{A+B}}}$
$y=(A+\overline{A+B})\cdot (B+\overline{A+B})$

A	B	Y
0	0	1
0	1	0
1	0	0
1	1	1