KCET 2014 Physics Solved Paper

The given digital circuit is shown as follows:Using Boolean law: A + A = A, we get
A+A=A and B+B=B
Using de Morgan’s theorem:A+B=A⋅B

−

A

+B=

−

A

⋅

−

B

and using

−

A

=A, we get

−

A

⋅

−

B

=A⋅B
Therefore, Y=A·B
Truth table

A	B	A+A	B+B	Y
0	0	1	1	0
0	1	1	0	0
1	0	0	1	0
0	0	1	1	1

Thus, the given digital circuit represents AND Gate.