Question

For which of the following inputs, output $Y$ is high $\left(1\right)?$

• A. $A=1,B=1,C=0$
• B. $A=1,B=0,C=1$
• C. $A=0,B=1,C=0$
• D. $A=1,B=0,C=0$

Answer 1

The correct option is B $A=1,B=0,C=1$


Output of gate $1$,

$Y_1=A+B$

Output of gate $2$,

$Y_2=Y_1.C=(A+B).C$

When $A=0,B=1,C=0$

Then $Y_2=(0+1).0=0$

If $A=1,B=0,C=0$

$Y_2=(1+0).0=0$
If $A=1,B=1,C=0$

$Y_2=(1+1).0=0$

If $A=1,B=0,C=1$

$Y_2=(1+0).1=1$