Question

A NOR gate and a NAND gate are connected as shown in the figure. Two different sets of inputs are given to this set up. In the first case, the input to the gates are A=0, B=0, C=1 and A=1, B=0, C=1 in the second case. The output D in the first case and second case respectively

 

A.0 and 0
B.0 and 1A
C.1 and 0
D.1 and 1

Answer 1

Hint: NOR gate is equivalent to the negation of the OR operator. It may also be seen as the inverse of an AND gate in some cases. A NAND gate is the complement to an AND gate.

Complete answer:
The NOR gate is a logic gate that is an implementation of logical NOR. It behaves in accordance to the truth table to the right. NOR gate is equivalent to the negation of the OR operator. It may also be seen as the inverse of an AND gate in some cases. A NAND gate is a logic gate which produces an output which is not true only if all its inputs are true. Therefore its output is the complement to AND gate.

CASE 1.) a=0,b=0,c=1
firstly the output of NOR gate is
$\overline{0\cdot 1}=1$
$\overline{A+B}=\overline{0+0}=1=E$
Secondly the output of NAND gate is
 $\overline{E\cdot C}=\overline{1\cdot 0}=1$

CASE 2.) a=1,b=0,c=1
Now the output of NOR gate will be
$\overline{1+0}=0$
And that of NAND gate will be
$\overline{0\cdot 1}=1$

So, the correct answer is “Option D”.

Note:
The Logic NAND Gate is commonly called a “Universal” gate because it is the mostly used logic gate type. NAND gates can be used in the production of other logic gates. For the production of NAND gate from NOR gate, we must invert all inputs to the NOR gate and also NOR gate's output.