ISRO-2013-22

Question

Any set of Boolean operators that is sufficient to represent all Boolean expressions is said to be complete. Which of the following is not complete ?

• A. {$NOT$, $OR$}
• B. {$NOR$}
• C. {$AND$, $OR$}
• D. {$AND$, $NOT$}

Answer 1

NAND AND NOR are universal gate  and with the help of these gates we can implement any other function. Hence they are called functionally complete

option a)

Not + Or = Nor gate only

option b ) It says NOR

option d ) And + not = NAND gate

So remaining is option c---which is answer :)

Comments

But answer given in answer key is option B

Answer 2

A) NOT + OR = NOR (complete)

B) NOR(complete)

C) AND + OR = (not complete)

D) AND + NOT = NAND(complete)

Answer 3

c

NAND & NOR is functionally complete which can also be represented as option d & a respectively.