# Multiple Choice Questions with Answers on Digital Electronics Circuits - Flip-Flops

1. A basic SR 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

2. The logic circuits whose outputs at any instant of time depends not only on the present inputs but also on the past outputs are called

a) Combinational circuits
b) Sequential circuits
c) Latches
d) Flip-flops

3. Operations of which circuits among the following are fastest?
a) Combinational circuits
b) Sequential circuits
c) Latches
d) Flip-flops

4. The basic latch consists of
a) Two inverters
b) Two comparators
c) Two amplifiers

5. In SR flip-flop, if Q = 0 the output is said to be
a) Set
b) Reset
c) Previous state
d) Current state

6. What is a trigger pulse?
a) A pulse that starts a cycle of operation
b) A pulse that reverses the cycle of operation
c) A pulse that prevents a cycle of operation
d) A pulse that enhances a cycle of operation

7. 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

8. The truth table of an SR flip-flop has how many valid entries?
a) 1
b) 2
c) 3
d) 4

9. The characteristic equation of SR latch is
a) Q(n+1) = (S + Q(n))R’
b) Q(n+1) = SR + Q(n)R
c) Q(n+1) = S’R + Q(n)R
d) Q(n+1) = S’R + Q'(n)R

10. What is the disadvantage of an SR flip-flop?
a) It has no Enable input
b) It has a RACE condition
c) It has no clock input
d) Invalid State

Hope this post on "MCQ on Digital Electronics with Answers - 6" will help Electronics Engineering and Electrical Engineering students in preparation of technical interviews, GATE, IES etc.