A directory of Objective Type Questions covering all the Computer Science subjects. Here you can access and discuss Multiple choice questions and answers for various compitative exams and interviews.

 21. The number of states in the minimal deterministic finite automaton corresponding to the regular expression (0 + 1)*(10) is ____________ a. 2 b. 3 c. 4 d. 5

 22. Let T be the language represented by the regular expression Σ∗0011Σ∗ where Σ = {0, 1}. What is the minimum number of states in a DFA that recognizes L' (complement of L)? a. 4 b. 5 c. 6 d. 8

 23. Which one of the following regular expressions is NOT equivalent to the regular expression (a + b + c) *? a. (a* + b* + c*)* b. (a*b*c*)* c. ((ab)* + c*)* d. (a*b* + c*)*

 24. Let L be a regular language and M be a context-free language, both over the alphabet Σ. Let Lc and Mc denote the complements of L and M respectively. Which of the following statements about the language Lc∪ Mc is TRUE? a. It is necessarily regular but not necessarily context-free b. It is necessarily context-free c. It is necessarily non-regular d. None of the above

 25. Which of the following statements is TRUE about the regular expression 01*0? a. It represents a finite set of finite strings b. It represents an infinite set of finite strings c. It represents a finite set of infinite strings d. It represents an infinite set of infinite strings

 26. The language {0^n 1^n 2^n | 1 ≤ n ≤ 10^6} is a. regular b. context-free but not regular c. context-free but its complement is not context-free d. not context-free

 27. A language L satisfies the Pumping Lemma for regular languages, and also the Pumping Lemma for context-free languages. Which of the following statements about L is TRUE? a. L is necessarily a regular language b. L is necessarily a context-free language, but not necessarily a regular language c. L is necessarily a non-regular language d. None of the above