UGC NET CSE | September 2013 | Part 2 | Question: 14

Question

Regular expression for the language $L=w \in \{0,1\}* \mid w$ has no pair of consecutive zeros $\}$ is

• A. $(1+010)*$
• B. $(01+10)*$
• C. $(1+010)*(0+ \lambda)$
• D. $(1+01)* (0+\lambda)$

Answer 1

ans is D

A gives 010010 which is not acceptable

B gives 1001  rejected

C gives 0100 again rejected

D is the right ans

Answer 2

(A)Regular Expression (1+010)* can accept 010010 hence we can eliminate this option.

(B)Regular Expression(01+10)* can accept 1001.Hence we can eliminate this option.

(C)Regular Expression (1+010)*(0+$\lambda$) can accept string 0100 Hence we can eliminate this option.

(D)Regular Expression (1+01)*(0+$\lambda$) will not generate no consecutive pairs of zeros.

Hence,Option(D)(1+01)*(0+$\lambda$).

Answer 3

A - 010010

B -1001

C -0100

D -Correct