question_answer

The output is low when either of the input is high, then this represents which of the following gates?

A)  OR           

B)  NOR

C)  AND          

D)  NAND

Correct Answer: B

Solution :

 Key Idea: NOR gate is universal gate. The NOT-OR operation is known as the NOR operation. Figure shows an N input \[(N\ge 2)\] OR gate followed by a NOT gate. The operation of this circuit can be described in the following way. The output of the OR gate V can be written as \[y=A+B+...+N\] ... (i) and the output of the NOT gate (Y) can be written using \[y=\overline{y}=\overline{A+B+...+N}\] ... (ii) The logic operation represented by Eq. (ii) is known as the NOR operation. or Table gives the truth table of a 2-input NOR gate. It indicates when either of input is high, the output is low.

	Inputs	Output
A	B	Y
0	0	1
0	1	0
1	0	0
1	1	0