Theory of Computation
Finite Automata and Regular Language
Marks 1Marks 2Marks 5
Push Down Automata and Context Free Language
Marks 1Marks 2
Undecidability
Marks 1Marks 2
Recursively Enumerable Language and Turing Machine
Marks 1Marks 2
1
GATE CSE 2016 Set 1
MCQ (Single Correct Answer)
+2
-0.6
Let $$X$$ be a recursive language and $$Y$$ be a recursively enumerable but not recursive language. Let $$W$$ and $$Z$$ be two languages such that $$\overline Y $$ reduces to $$W,$$ and $$Z$$ reduces to $$\overline X $$ (reduction means the standard many-one reduction). Which one of the following statements is TRUE?
A
$$W$$ can be recursively enumerable and $$Z$$ is recursive.
B
$$W$$ can be recursive and $$Z$$ is recursively enumerable.
C
$$W$$ is not recursively enumerable and $$Z$$ is recursive.
D
$$W$$ is not recursively enumerable and $$Z$$ is not recursive.
2
GATE CSE 2014 Set 2
MCQ (Single Correct Answer)
+2
-0.6
Let $$ < M > $$ be the encoding of a Turing machine as a string over $$\sum { = \left\{ {0,1} \right\}.} $$
Let $$L = \left\{ { < M > \left| M \right.} \right.$$ is a Turing machine that accepts a string of length $$\left. {2014} \right\}.$$ Then, $$L$$ is
A
decidable and recursively enumerable
B
un-decidable but recursively enumerable
C
un-decidable and not recursively enumerable
D
decidable but not recursively enumerable
3
GATE CSE 2014 Set 1
MCQ (Single Correct Answer)
+2
-0.6
Let $$L$$ be a language and $$\overline L $$ be its complement. Which one of the following is NOT a viable possibility?
A
Neither $$L$$ nor $$\overline L $$ is recursively enumerable (r.e).
B
One of $$L$$ and $$\overline L $$ is r.e. but not recursive; the other is not r.e.
C
Both $$L$$ and $$\overline L $$ are r.e. but not recursive.
D
Both $$L$$ and $$\overline L $$ are recursive.
4
GATE CSE 2008
MCQ (Single Correct Answer)
+2
-0.6
If $$L$$ and $$\overline L $$ are recursively enumerable then $$L$$ is
A
Regular
B
Context-free
C
Context-sensitive
D
Recursive.
GATE CSE Subjects
Theory of Computation
Operating Systems
Algorithms
Digital Logic
Database Management System
Data Structures
Computer Networks
Software Engineering
Compiler Design
Web Technologies
General Aptitude
Discrete Mathematics
Programming Languages
Computer Organization