Question

The S-R latch composed of NAND gates is called an active low circuit because _____________

(a) It is only activated by a positive level trigger

(b) It is only activated by a negative level trigger

(c) It is only activated by either a positive or negative level trigger

(d) It is only activated by sinusoidal trigger

The question was asked during an internship interview.

The doubt is from Triggering of Flip Flops in section Flip-Flops of Digital Circuits

Answer 1

Correct choice is (b) It is only activated by a negative level trigger

The best I can explain: Active low indicates that only an input value of 0 sets or resets the circuit.