Question

A universal logic gate is one which can be used to generate any logic function. Which of the following is a universal logic gate?

(a) OR

(b) AND

(c) XOR

(d) NAND

This question was addressed to me during an interview.

Asked question is from Logic Gates and Networks in section Boolean Algebra and Minimization Techniques and Logic Gates of Digital Circuits

Answer 1

Right choice is (d) NAND

Easiest explanation: An Universal Logic Gate is one which can generate any logic function and also the three basic gates: AND, OR and NOT. Thus, NOR and NAND can generate any logic function and are thus Universal Logic Gates.