Question

A basic S-R flip-flop can be constructed by cross-coupling of which basic logic gates?

(a) AND or OR gates

(b) XOR or XNOR gates

(c) NOR or NAND gates

(d) AND or NOR gates

The question was asked during an interview.

My question comes from Flip Flops in chapter Flip-Flops of Digital Circuits

Answer 1

The correct answer is (c) NOR or NAND gates

For explanation I would say: The basic S-R flip-flop can be constructed by cross coupling of NOR or NAND gates. Cross coupling means the output of second gate is fed to the input of first gate and vice-versa.