Reqular Expressions Questions

MCQ bookmark_border

31.

L and ~L are recursive enumerable then L is

A

Regular

B

Context free

C

Context sensitive

D

Recursive

Correct Answer: D

If L is recursive enumerable and its complement too if and only if L is recursive.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

32.

Regular expressions are closed under

A

Union

B

Intersection

C

Kleen star

D

All of the mentioned

Correct Answer: D

According to definition of regular expression.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

33.

A regular language over an alphabet a is one that can be obtained from

A

union

B

concatenation

C

kleene

D

All of the mentioned

Correct Answer: D

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

34.

Regular expression {0,1} is equivalent to

A

0 U 1

B

0 / 1

C

0 + 1

D

All of the mentioned

Correct Answer: D

All are equivalent to union operation.

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

35.

Precedence of regular expression in decreasing order is

A

* , . , +

B

. , * , +

C

. , + , *

D

+ , a , *

Correct Answer: A

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

36.

Regular expression ?* is equivalent to

A

?

B

?

D

1

Correct Answer: A

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

37.

a? is equivalent to

A

a

B

a+?

C

a+?

D

wrong expression

Correct Answer: C

Zero or one time repetition of previous character .

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

38.

?L is equivalent to

A

?

B

?

C

L

D

??

Correct Answer: C

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

39.

(a+b)* is equivalent to

A

b*a*

B

(a*b*)*

C

a*b*

D

none of the mentioned

Correct Answer: B

Check Answer report_problem Report forum Discussion

MCQ bookmark_border

40.

?L is equivalent to

A

L? & ?

B

? & L

C

L & L

D

? & L

Correct Answer: A

Check Answer report_problem Report forum Discussion