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 Y 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