All Exams Test series for 1 year @ ₹349 only
Question

What is the minimum and maximum number of initial, dead, unreachable and final states in a valid ‘n’ state finite automaton, where the language accepted is not ‘φ’?

This question was previously asked in
UGC NET 2022 Paper 1 Question Paper (22-Oct-2022) (Shift 2)
The correct answer is

Minimum: 1,0,0,1; Maximum: 1, (n-1), (n-1), n

A finite automaton has exactly one initial state; a dead (sink) state is a non-final state from which no final state can be reached; an unreachable state cannot be reached from the initial state. The language must be non-empty, so some final state is reachable from the start.

Step 1 — Initial states: exactly one, so minimum 1 and maximum 1.

Step 2 — Dead states: a minimal DFA may need none, so the minimum is 0. The initial state can never be dead (the language is not empty), so at most the other \(n-1\) states are dead, e.g. when the initial state is final and every other state is dead.

Step 3 — Unreachable states: minimum 0. The initial state is always reachable, so at most \(n-1\) states are unreachable (initial state final, all others unreachable).

Step 4 — Final states: at least 1 is needed for a non-empty language, and all n states may be final, so minimum 1 and maximum n.

Codes with a minimum of 1 dead and 1 unreachable state, or 0 final states, contradict Steps 2–4, and a code with n dead states or n minimum final states is impossible.

Minimum: 1,0,0,1; Maximum: 1, (n-1), (n-1), n option is correct.

Was this answer helpful?

Similar Questions

  1. There are exactly __________ different finite automata with three states x, y and z over the alphabet {a, b} where x is always the start state.

  2. The transition function for the language \(L = \{w \mid n_{a}(w)\) and \(n_{b}(w)\) are both odd\(\}\) is given by :

    \(\delta(q_{0}, a) = q_{1}\) ; \(\delta(q_{0}, b) = q_{2}\)

    \(\delta(q_{1}, a) = q_{0}\) ; \(\delta(q_{1}, b) = q_{3}\)

    \(\delta(q_{2}, a) = q_{3}\) ; \(\delta(q_{2}, b) = q_{0}\)

    \(\delta(q_{3}, a) = q_{2}\) ; \(\delta(q_{3}, b) = q_{1}\)

    The initial and final states of the automata are :

  3. Minimal deterministic finite automaton for the language \(L = \{0^{n} \mid n \geq 0, n \neq 4\}\) will have :

  4. For the above specified passage, which of the following is DFA for the language represented/accepeted by machine?

  5. For the above mentioned passage which of the following is correct?

  6. Which of the following represented the minimum state DFA for the above specified passage?

  7. Which of the following languages can be recognized by neither Non-Deterministic Finite Automata (NFA) nor Deterministic Finite Automata (DFA) ?

    (A) L1 = {w ∈ {0, 1}* | the length of w is even}

    (B) L2 = {w ∈ {0, 1}* | the length of w is odd}

    (C) L3 = {w ∈ {0, 1}* | all 0′s come before all 1′s in w}

    (D) L4 = {w ∈ {0, 1}* | w contains an equal number of 0′s and 1′s}

    (E) L5 = {w ∈ {0, 1}* | all 1′s come before all 0′s in w}

    Choose the correct answer from the options given below :

  8. Which of the following Finite Automata, recognizes the language L={a,b}* ?

    A. M=({q0}, {a,b}, δ, q0, {q0}) where, δ is

    ab
    q0{q0}{q0}

    B. M=({q0,q1}, {a,b}, δ, q0, {q0,q1}) where, δ is

    ab
    q0{q0,q1}{q0,q1}
    q1{q1}{q1}

    C. M=({q0,q1}, {a,b}, δ, q0, {q0,q1}) where, δ is

    ab
    q0{q0,q1}{q0}
    q1-{q1}

    D. M=({q0,q1,q2 }, {a,b}, δ, q0, {q0}) where, δ is

    ab
    q0{q0}{q0}
    q1{q2}-
    q2{q0}{q2}
  9. Let L be the language generated by regular expression 0*10* and accepted by the deterministic finite automata M, whose transition table is given below (start state a; final states c, d and e).

    State01
    abc
    bad
    cef
    def
    eef
    fff

    Consider the relation RM defined by M. As all states are reachable from the start state, RM has _____ equivalence classes.


Important Questions from Finite Automata

  1. Consider the DFA given below

    Which of the regular expressions given below represents the above DFA ?

  2. Let $M$ be a nondeterministic finite automaton (NFA) with 6 states over a finite alphabet.
    Which of the following options CANNOT be the number of states in the minimal deterministic finite automaton (DFA) that is equivalent to $M$ ?
  3. Consider the following deterministic finite automaton (DFA) defined over the alphabet, Σ = {𝑎, 𝑏}. Identify which of the following language(s) is/are accepted by the given DFA.

  4. Consider a finite state machine (FSM) with one input 𝑋 and one output 𝑓, represented by the given state transition table. The minimum number of states required to realize this FSM is ________. (Answer in integer)

    Present stateNext stateOutput f
    X = 0X = 1X = 0X = 1
    AFB00
    BDC00
    CFE00
    DGA10
    EDC00
    FFB11
    GH001
    HGA10
  5. Consider the following DFA that generates set of strings over $\Sigma=\{a, b, c\}$

    Now identify that which of the followings is the best description of the language for the above DFA

Need Expert Advice?
Upcoming Exams
CTET
December 12, 2026
CBSE UGC NET
December 14, 2026
CSIR UGC NET
December 19, 2026
Test Series
UGC NET img
Teaching
UGC NET (Paper 2) 2026 Mock Test Series
796 Tests 2 Tests Free
4.4(40)
English
More Questions from UGC NET

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App