Question

The logic behind NOR gate is that which gives

• A. high output when both inputs are high
• B. low output when both inputs are low
• C. high output when both inputs are low
• D. none of these

Answer 1

Answer: (C)

high output when both inputs are low

Let the inputs of NOR gate be $a,b$

The output of NOR gate will be $X=\overline{a+b}$

If $a=0$ and $b=0$ then $X=1$

If $a=0$ and $b=1$ then $X=0$

If $a=1$ and $b=0$ then $X=0$

If $a=1$ and $b=1$ then $X=0$

Therefore the output will be high when both the inputs are low

So the correct option is $C.$