Write the truth table for the circuit shown in Fig. Name the gate of which this circuit is performing.

Explanation

Here, `y_(1)=bar(A.B)=barA+barB`
`y_(2)=A+B`
`y=y_(1).y_(2)`
`=(bar(A.B)).(A+B)`
`=(barA+barB).(A+B)`
`=bar.(A+B)+bar.(A+B)`
`=bar.A+bar.B+bar.A+bar.B`
`0+bar.B+bar.A+0`
`=A.bar+B.bar`
It is a Boolean expression of XOR gate.
Thus XOR gate is produced.
Truth table of this gate is given below.
`|{:(A,B,y_(1)=bar(A.B),y_(2)=A+B,y=(bar(A.B)).(A+B)),(0,0,1,0,0),(0,1,1,1,1),(1,0,1,1,1),(1,1,0,1,0):}|`