Welcome to the Regular Expressions MCQs Page

Dive deep into the fascinating world of Regular Expressions with our comprehensive set of Multiple-Choice Questions (MCQs). This page is dedicated to exploring the fundamental concepts and intricacies of Regular Expressions, a crucial aspect of Formal Languages and Automata Theory. In this section, you will encounter a diverse range of MCQs that cover various aspects of Regular Expressions, from the basic principles to advanced topics. Each question is thoughtfully crafted to challenge your knowledge and deepen your understanding of this critical subcategory within Formal Languages and Automata Theory.

Check out the MCQs below to embark on an enriching journey through Regular Expressions. Test your knowledge, expand your horizons, and solidify your grasp on this vital area of Formal Languages and Automata Theory.

Note: Each MCQ comes with multiple answer choices. Select the most appropriate option and test your understanding of Regular Expressions. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

Regular Expressions MCQs | Page 3 of 15

Explore more Topics under Formal Languages and Automata Theory

01

Basics of Automata Theory

02

Finite Automata

03

DFA Minimization

04

Context Free Grammars

05

Regular Languages

06

Push Down Automata

07

Context Free Languages

08

Introduction to Turing Machines

09

Undecidability and Intractable Problems

Q21.

Which of the following pairs of regular expression are equivalent?

1(01)* and (10)*1

X(xx)* and (xx)*x

None of the mentioned

Both of the mentioned

Discuss

Answer: (d).Both of the mentioned

Q22.

Which of the following identity is true?

Ɛ +RR* = R* = ɛ + R*R

(R1R2)*R1 = R1 (R2R1)*

R*R* = R*

All of the mentioned

Discuss

Answer: (d).All of the mentioned

Q23.

The set of all strings over ∑ = {a,b} in which all strings having bbbb as substring is

(a+b)* bbbb (a+b)*

(a+b)* bb (a+b)*bb

bbb(a+b)*

bb (a+b)*

Discuss

Answer: (a).(a+b)* bbbb (a+b)*

Q24.

The set of all strings over ∑ ={a,b} in which a single a is followed by any number of b’s a single b followed by any number of a’s is

ab* + ba*

ab*ba*

a*b + b*a

None of the mentioned

Discuss

Answer: (a).ab* + ba*

Q25.

Regular expressions are used to represent which language

Recursive language

Context free language

Regular language

All of the mentioned

Discuss

Answer: (c).Regular language

Q26.

The set of all strings over ∑ = {a,b} in which strings consisting a’s and b’s and ending with in bb is

a*bbb

(a+b)* bb

All of the mentioned

Discuss

Answer: (c).(a+b)* bb

Q27.

If P, Q, R are three regular expressions and if P does not contain a then the equation R = R + RP has a unique solution given by

R = QP*

R = P*Q

R = RP

None of the mentioned

Discuss

Answer: (a).R = QP*

Q28.

Which of the following regular expression denotes zero or more instances of an a or b?

a/b

(a/b)*

(ab)*

a*Ib

Discuss

Answer: (b).(a/b)*

Q29.

The string (a)|((b)*(c)) is equivalent to

Empty

abcabc

b*c|a

None of the mentioned

Discuss

Answer: (c).b*c|a

Q30.

How many strings of length less than 4 contains the language described by the regular expression (x+y)*y(a+ab)* ?

Discuss

Answer: (d).11

Page 3 of 15

Welcome to the Regular Expressions MCQs Page

Regular Expressions MCQs | Page 3 of 15

Explore more Topics under Formal Languages and Automata Theory

Basics of Automata Theory

Finite Automata

DFA Minimization

Context Free Grammars

Regular Languages

Push Down Automata

Context Free Languages

Introduction to Turing Machines

Undecidability and Intractable Problems

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