Automata Theory Multiple Choice Quaestion & Answers (MCQs) set-24

1. Given Language: L= {ab U aba}*
If X is the minimum number of states for a DFA and Y is the number of states to construct the NFA,
|X-Y|=?
a) 2
b) 3
c) 4
d) 1

2. Transition function maps.
a) S * Q -> S
b) Q * Q -> S
c) S * S -> Q
d) Q * S -> Q
3. A binary string is divisible by 4 if and only if it ends with:
a) 100
b) 1000
c) 1100
d) 0011
4. Statement 1: NFA computes the string along parallel paths.
Statement 2: An input can be accepted at more than one place in an NFA.
Which among the following options are most appropriate?
a) Statement 1 is true while 2 is not
b) Statement 1 is false while is not
c) Statement 1 and 2, both are true
d) Statement 1 and 2, both are false
5. Design a NFA for the language:
L: {an| n is even or divisible by 3}
Which of the following methods can be used to simulate the same.
a) e-NFA
b) Power Construction Method
c) Both (a) and (b)
d) None of the mentioned
6. Which among the following looks similar to the given expression?
((0+1). (0+1)) *
a) {x? {0,1} *|x is all binary number with even length}
b) {x? {0,1} |x is all binary number with even length}
c) {x? {0,1} *|x is all binary number with odd length}
d) {x? {0,1} |x is all binary number with odd length}

7. Which of the following regular expressions represents the set of strings which do not contain a substring ‘rt’ if ?= {r, t}
a) (rt)*
b) (tr)*
c) (r*t*)
d) (t*r*)

8. Concatenation Operation refers to which of the following set operations:
a) Union
b) Dot
c) Kleene
d) Two of the options are correct

9. It is suitable to use ____________ method/methods to convert a DFA to regular expression.
a) Transitive Closure properties
b) Brzozowski method
c) State elimination method
d) All of the mentioned
10. Which of the following pair of regular expression are not equivalent?
a) 1(01)* and (10)*1
b) x(xx)* and (xx)*x
c) (ab)* and a*b*
d) x+ and x*x+

11. Which of the following is true?
a) Every subset of a regular set is regular
b) Every finite subset of non-regular set is regular
c) The union of two non regular set is not regular
d) Infinite union of finite set is regular

12. Given segment of code:
$string1 = “Hello\nWorld\n”;
if ($string1 =~ m/d\n\z/) {
print “$string1 is a string “;
print “that ends with ‘d\\n’.\n”;
}
What does the symbol /z does?
a) changes line
b) matches the beginning of a string
c) matches the end of a string
d) none of the mentioned
13. State true or false:
Statement: A regular expression is a sequence of characters that represent a pattern.
a) true
b) false
14. Which of the following options support the given statement?
Statement: A regular expression could be a fixed word or describe something like more general.
a) This flexibility makes Regular expression invaluable.
b) This flexibility makes the Regular expression unvaluable.
c) Both (a) and (b)
d) None of the mentioned
15. The methodology to show an error when the analyzer faces a keyword over an user’s input is based on:
a) rule priority
b) longest match rule
c) keyword-out rule
d) none of mentioned