Question

The Boolean expression of the output y in terms of the input A and B for the circuit shown in figure.

A. `barAB+AbarB`
B. AB
C. `AB+barAbarB`
D. `AbarB+1`

Answer 1

Correct Answer - C
The output from the upper AND gate =`(barA.B)`
The output from the lower AND gate =`(A.barB)`
The output y of the NOR gate is
`y=bar((barA.B)+(A.barB))`
`=bar((barA.B))+bar((A.barB))=(A+barB)(barA+B)`
`=AbarA+AB+barBbarA+barB B=AB+barAbarB`