Regular Expressions
1.

The grammar defined by regular expressions is known as?
A.  

regular language

 B.  

regular grammar

 C.  

regular notations

 D.  

regular operation
2.

The language defined by regular grammar is known as?
A.  

regular language

 B.  

regular grammar

 C.  

regular notations

 D.  

regular operation
3.

Union of two languages L and M is written as?
A.  

LM = {st | s is in L and t is in M}

 B.  

L+M

 C.  

L*M

 D.  

L U M = {s | s is in L or s is in M}
4.

Concatenation (.) has the ________ highest precedence
A.  

first

 B.  

second

 C.  

third

 D.  

fourth
5.

Which of them are not left associative ?
A.  

*

 B.  

|

 C.  

plus(+)

 D.  

.
6.

The RE in which any number of 0′s is followed by any number of 1′s followed by any number of 2′s is?
A.  

(0+1+2)*

 B.  

0*1*2*

 C.  

0* + 1 + 2

 D.  

(0+1)*2*
7.

Which of the following is NOT the set of regular expression R = (ab + abb)* bbab?
A.  

ababbbbab

 B.  

abbbab

 C.  

ababbabbbab

 D.  

abababab
8.

Consider the production of the grammar S->AA A->aa A->bb Describe the language specified by the production grammar.
A.  

L = {aaaa,aabb,bbaa,bbbb}

 B.  

L = {abab,abaa,aaab,baaa}

 C.  

L = {aaab,baba,bbaa,bbbb}

 D.  

L = {aaaa,abab,bbaa,aaab}
9.

If R is regular language and Q is any language (regular/ non regular), then Pref (Q in R) is _____________
A.  

Non-regular

 B.  

Equal

 C.  

Infinite

 D.  

Regular
10.

The non terminal that gives null will said to have a null production
A.  

TRUE

 B.  

FALSE

 C.  

Can be true or false

 D.  

Can not say