CS401 T02

1. What does the regular expression (0 + 1)* represent?

• Strings of alternating 0s and 1s

• All binary strings, including the empty string

• Strings containing only 1s

• Strings ending with a 1

2. Which of the following operations is not part of Kleene operators?

• Union (+)

• Concatenation

• Star (*)

• Division (/)

3. What does the regular expression a*b represent?

• Strings containing only b

• Strings containing zero or more a's followed by one b

• Strings ending with b

• Strings with a and b alternating

4. Which string is not in the language of the regular expression (ab + ba)*?

• abab

• baba

• abbba

• ε

5. What does the regular expression 0+11+101 represent?

• Strings starting with 0 and ending with 1

• Strings containing either "0", "11", or "101"

• Binary strings of length 2

• Strings with alternating 0s and 1s

6. What is true for any regular language?

• It cannot be expressed using a DFA

• It can only be described by a regular expression

• It can be accepted by both DFA and NFA

• It always contains the empty string

7. According to Kleene's Theorem, a language is regular if and only if:

• It can be described using a finite automaton

• It has infinite strings

• It is accepted by a Turing machine

• It has no ε-transitions

8. Which statement is true about ε in regular expressions?

• It represents a single space character

• It matches any single character

• It is not part of regular expressions

• It denotes the empty string

9. What does the expression (a + b)(a + b)* represent?

• All binary strings of odd length

• All binary strings except the empty string

• Strings starting with a

• Strings containing only a

10. Which is a practical application of regular expressions?

• Data compression

• Binary sorting

• Tokenizing programming languages

• Image processing