# Logic Design Questions and Answers – State Reduction and State Assignment

This set of Logic Design Multiple Choice Questions & Answers (MCQs) focuses on “State Reduction and State Assignment”.

1. What is the importance of equivalent states?
a) To simplify the circuitry
b) To change the flow of operation
c) To change the result of the operation
d) T reduce propagation delay

Explanation: State tables are used to describe different states of any finite state machine. If the present state, next state and output of any two states are same then they are called as equivalent states. Any number of equivalent states are simplified to one state to simplify the circuitry.

2. When two states of a state table are termed as equivalent states?
a) Only if the outputs are same
b) Only if the present states are same
c) If the next states are same
d) If the present state, next state and output are same

Explanation: State tables are used to describe different states of any finite state machine. If the present state, next state and output of any two states are same then they are called as equivalent states.

3. How many equivalent states are there in the following state table?

```
PS             NS            O
a                  b             c
b                  f              g
d                  a              c
a                  b              c
d                  e              a
a                  b              c
```

a) 1
b) 2
c) 3
d) 4

Explanation: State tables are used to describe different states of any finite state machine. Such a table is shown in the diagram. The 1st, 4th and 6th row have same present state, next state and output. So, they will be termed as equivalent states.

4. Which two states are redundant states in the following table?

a) a and b
b) d and f
c) a and f
d) e and f

Explanation: Any two states in a state table having identical present state, next state and output then they are termed as equivalent states. It is clear from the state table that states d and f have absolutely equivalent next state and output configuration. So they can be considered as equivalent states.

5. Which of the following operations are preformed to find redundant states in any state table?
a) Row matching
b) Column matching
c) Matrix matching
d) Table matching

Explanation: In the state tables, each state, their output and next states are represented in a single row. Hence, we have to perform row matching to find two equivalent states. So the correct answer is row matching.

6. Which of the following CAD tools accepts logic circuits, state table or state graphs as input and generates minimized logic equations?
a) Schematic capture
b) Simulation
c) Generation and minimization of logic equations
d) SimUaid

Explanation: The process of generation and minimization of logic equations accepts logic diagrams, state graphs or tables as input and generates minimized logic equations. All these processes are essential for CAD designing.

7. What is the feature of the tool “Schematic capture”?
a) Generating minimized logic equations
b) Generating PLA/PAL designing files for PLD designers
c) Creating and editing logic diagrams for logic design
d) Virtually simulating any circuit

Explanation: Schematic capture is a tool where the related programs allow the designer to interactively create or edit various types of logic circuits. For this purpose it also provides various libraries and components such as logic gates, flip-flops, registers, counters etc.

Sanfoundry Global Education & Learning Series – Logic Design.