question_answer

Which logic gate is represented by the following combination of logic gates?

A)  OR                        

B)         NOR                     

C)         AND         

D)         NAND

Correct Answer: C

Solution :

                Output of gate-1, \[{{Y}_{1}}=\bar{A}\] Output of gate-2, \[{{Y}_{2}}=\bar{B}\] Output of gate-3, \[Y=\overline{{{Y}_{1}}+{{Y}_{2}}}=\overline{\bar{A}+\bar{B}}\]                      \[=\bar{\bar{A}}\,\bar{\bar{B}}\]                      \[=A\,B\] which is the output of AND gate.