Flip-Flops and Timers - Technical MCQs

Q1:

Which of the following is correct for a gated D-type flip-flop?

A The Q output is either SET or RESET as soon as the D input goes HIGH or LOW.

B The output complement follows the input when enabled.

C Only one of the inputs can be HIGH at a time.

D The output toggles if one of the inputs is held HIGH.

ANS:A - The Q output is either SET or RESET as soon as the D input goes HIGH or LOW.

Why on the earth is everybody thinking about clock? Of course the clock must be high that the D-f/f is working.

Now, D-f/f is also called TRANSPARENT FLIP FLOP. Since it gives the same value in the output as in the input.

[input=D, output=Q].

D=0, Q=0.

D=1, Q=1.

This is the condition of option(A).

Now read (A) option carefully:

"The Q output is either SET(1) or RESET(0) as soon as the D input goes HIGH(1) or LOW(0)".