# Digital Electronics 4

Electronic Engineering MCQ Question Papers: ENTC, IT Interview Placement

Subject:  Digital Electronics 4

Part 4: List for questions and answers of Digital Electronics

Q1. The design of clocked sequential circuit requires

a) The state reduction

b) The state assignment

c) The design of next state decoder

d) All of the above

Q2. In a sequential circuit design, state reduction is done for designing the circuit with

a) A minimum no.of flipflops

b) A minimum no.of gates

c) A minimum no.of gates and memory elements

d) None of above

Q3. A sequential circuit with ten states will have

a) 10 flipflops

b) 5 flipflops

c) 4 flipflops

d) 0 flipflops

Q4. The output of a clocked sequential circuit is independent of the input.the circuit can be represented by

a) Melay model

b) Moore model

c) Either melay or moore model

d) Neither melay nor moore model

Q5. For designing a finite state machine K-maps can be used for minimising the

a) Excitation expressions of flipflops

b) No.of flipflops

c) Output logic expressions

d) Output logic expressions

Q6. While constructing a state diagram of sequential circuit from set of given statements,

a) A minimum no.of states must only be used

b) Redundant states may be used

c) Redundant states must be avoided

d) Redundant states must be avoided

Q7. A finite state machine

a) Is same as clocked sequential circuit

b) Consists of combinational logic circuits only

c) Consists of electrical motors

d) Does not exists in practice

Q8. The no.of directed arcs emanating from any state in a state diagram is

a) 2n ,where n is no.of inputs

b) Independent of no.of inputs

c) An arbitrary no

d) 2n ,where n is no.of flipflops

Q9. The no.of directed arcs terminating on any state of a state diagram is

a) 2n ,where n is no.of inputs

b) 2n ,where n is no.of flipflops in the circuits

c) Independent of no.of inputs

d) Dependent of no.of outputs

Q10. The ___node_________of the state diagram represents the states of the machine

a) Node

b) Arc

c) Vertex

d) Transition

Q11. The output values of physical devices are referred to as ___state variables_________.

a) State inputs

b) State outputs

c) State variables

d) Next state

Q12. State diagram can also be called the __transition____________diagram.

a) State table

b) Excitation table

c) Transition table

d) None of above

Q13. The next state part of the state table is called the __tansition__________table

a) State table

b) Excitation table

c) Transition table

d) None of above

Q14. The process of assigning the states of a physical device to the states of a sequential machine is known a ___state assignment________.

a) State reduction

b) State assignment

c) State table

d) States

Q15. Two states are said to be equivalent if

a) If set of inputs generate exactly the same output

b) If set of inputs generate exactly the same output and same next state

c) If set of inputs generate exactly the same next state

d) All above

Q16. How many flip-flops are required for dividing the frequency by 64?

a) 4

b) 5

c) 6

d) 8

Q17. The number of flip-flops are required to build a mod-15 counter is ……..

a) 4

b) 5

c) 6

d) 7

Q18. A ring counter is same as

a) A ring counter is same as

b) parallel counter

c) shift registers

d) none of these

Q19. In sequential circuits, their outputs at any instant of time depends ……..

a) Only on the inputs present at that instant of time

b) On past output as well as present inputs

c) Only on the past inputs

d) Only on the past inputs

Q20. A divide by 78 counters can be realized by using …….

a) 6 numbers of mod-13 counters

b) 13 numbers of mod-6 counters

c) One mod-13 counter followed by one mod-6 counter

d) 13 numbers of mod-13 counters

Part 4: List for questions and answers of Digital Electronics