1. Complement of (a + b)* will be
a. phi
b. null
c. a
d. b
Ans- a. phi
2. Which of the following is type 3 language ?
a. Strings of 0's whose length is perfect square
b. Palindromes string
c. Strings of 0's having length prime number
d. String of odd number of 0's
Ans- d. String of odd number of 0's
3. (a ^ 5b ^ 5)* is example of ____
a. Type 0 language
b. Type 1 language
c. Type 2 language
d. Type 3 language
Ans- d. Type 3 language
4. Homomorphism of a regular set is ___
a. Universal set
b. Null set
c. Regular set
d. Non regular set
Ans- c. Regular set
5. A _____ is a substitution such that h(a) contains a string for each a.
a. Closure
b. Interchange
c. Homomorphism
d. Inverse Homomorphism
Ans- c. Homomorphism
6. Reverse of (0+1)* will be:
a. Phi
b. Null
c. (0+1)*
d. (0+1)
Ans- c. (0+1)*
7. Reverse of a DFA can be formed by:
a. using PDA
b. making final state as non-final
c. making final as starting state and starting state as final state
d. None of the mentioned
Ans- c. making final as starting state and starting state as final state
8. If L1 is regular L2 is unknown but L1-L2 is regular ,then L2 must be:
a. Empty set
b. CFG
c. Decidable
d. Regular
Ans- d. Regular
9. If L1 and L2 are regular sets then intersection of these two will be:
a. Regular
b. Non Regular
c. Recursive
d. Non Recursive
Ans- a. Regular
10. Complement of regular sets are ___
a. Regular
b. CFG
c. CSG
d. RE
Ans- a. Regular