Automata Theory Multiple Choice Questions on “Programming Techniques-Storage and Subroutines”.
1. A turing machine has ____________ number of states in a CPU.
a) finite
b) infinte
c) May be finite
d) None of the mentioned
Answer: a
Clarification: A turing machine has finite number of states in its CPU. However the states are not small in number. Real computer consist of registers which can store values (fixed number of bits).
2. Suppose we have a simple computer with control unit holding a PC with a 32 bit address + Arithmetic unit holding one double length 64 bit Arithmetic Register. The number of states the finite machine will hold:
a) 2(32*64)
b) 296
c) 96
d) 32
Answer: b
Clarification: According to the statistics of the question, we will have a finite machine with 2^96 states.
3. Which of the following is/are not true for recursively ennumerable language?
a) partially decidable
b) Turing acceptable
c) Turing Recognizable
d) None of the mentioned
Answer: d
Clarification: In automata theory, a formal language is called recursively ennumerable language or partially decidable or semi decidable or turing acceptable or turing recognizable if there exists a turing machine which will ennumerate all valid strings of the language.
4. According to Chomsky hierarchy, which of the following is adopted by Recursively Ennumerable language?
a) Type 0
b) Type 1
c) Type 2
d) Type 3
Answer: a
Clarification: Recursively Ennumerable languages are type 0 languages in the Chomsky hierarchy. All regular, context free, context sensitive languages are recursivelyennumerable language.
5. Statement 1: Multitrack Turing machine.
Statement 2: Gamma is Cartesian product of a finite number of finite sets.
Which among the following is the correct option?
a) Statement 1 is the assertion and Statement 2 is the reason
b) Statement 1 is the reason and Statement 2 is the assertion
c) Statement 1 and Statement 2 are independent from each other
d) None of the mentioned
Answer: a
Clarification: Cartesian product works like a struct in C/C++. For Example: Computer tape storage is something like 8 or 9 bits in each cell. One can recognize a multi track tape machine by looking at the transitions because each will have tuples as the read and write symbols.
6. A multi track turing machine can described as a 6-tuple (Q, X, S, d, q0, F) where X represents:
a) input alphabet
b) tape alphabet
c) shift symbols
d) none of the mentioned
Answer: b
Clarification: The 6-tuple (Q, X, S, d, q0, F) can be explained as:
Q represents finite set of states,
X represents the tape alphabet,
S represents the input alphabet
d represents the relation on states and the symbols
q0 represents the initial state
F represents the set of final states.
7. Which of the following statements are false?
a) A multi track turing machine is a special kind of multi tape turing machine
b) 4-heads move independently along 4-tracks in standard 4-tape turing machine
c) In a n-track turing machine, n head reads and writes on all the tracks simultaneously.
d) All of the mentioned
Answer: c
Clarification: In a n-track turing machine, one head reads and writes on all the tracks simultaneously.
8. State true or false:
Statement: Two track turing machine is equivalent to a standard turing machine.
a) true
b) false
Answer: a
Clarification: This can be generalized for n- tracks and can be proved equivalent using ennumerable languages.