# Automata Theory Questions and Answers – Turing Machine-Notation and Transition Diagrams

This set of Automata Theory Interview Questions and Answers for freshers focuses on “Turing Machine – Notation and Transition Diagrams”.

1. A turing machine is a
a) real machine
b) abstract machine
c) hypothetical machine
d) more than one option is correct

Explanation: A turing machine is abstract or hypothetical machine thought by mathematician Alan Turing in 1936 capable of simulating any algorithm, however complicated it is.

2. A turing machine operates over:
a) finite memory tape
b) infinite memory tape
c) depends on the algorithm
d) none of the mentioned

Explanation: The turing machine operates on an infinite memory tape divided into cells. The machine positions its head over the cell and reads the symbol.

3. Which of the functions are not performed by the turing machine after reading a symbol?
a) writes the symbol
b) moves the tape one cell left/right
c) proceeds with next instruction or halts
d) none of the mentioned

Explanation: After the read head reads the symbol from the input tape, it performs the following functions:
a) writes a symbol(some model allow symbol erasure/no writing)
b) moves the tape left or right (some models allows no motion)
c) proceeds with subsequent instruction or goes either into accepting halting state or rejecting halting state.

4. ‘a’ in a-machine is :
a) Alan
b) arbitrary
c) automatic
d) None of the mentioned

Explanation: The turing machine was invented by Alan turing in 1936. He named it as a-machine(automatic machine).

5. Which of the problems were not answered when the turing machine was invented?
a) Does a machine exists that can determine whether any arbitrary machine on its tape is circular.
b) Does a machine exists that can determine whether any arbitrary machine on its tape is ever prints a symbol
c) Hilbert Entscheidungs problem
d) None of the mentioned

Explanation: Invention of turing machine answered a lot of questions which included problems like decision problem, etc.) . Alan was able to prove the properties of computation using such model.

6. The ability for a system of instructions to simulate a Turing Machine is called _________
a) Turing Completeness
b) Simulation
c) Turing Halting
d) None of the mentioned

Explanation: Turing Completeness the ability for a system of instructions to simulate a Turing machine. A programming language that is Turing complete is theoretically capable of expressing all tasks accomplishable by computers; nearly all programming languages are Turing complete.

7. Turing machine can be represented using the following tools:
a) Transition graph
b) Transition table
c) Queue and Input tape
d) All of the mentioned

Explanation: We can represent a turing machine, graphically, tabularly and diagramatically.

8. Which of the following is false for an abstract machine?
a) Turing machine
b) theoretical model of computer
c) assumes a discrete time paradigm
d) all of the mentioned

Explanation: A n abstract machine also known as abstract computer, is a theoretical model of computer or hardware system in automata theory. Abstraction in computing process usually assumes a discrete time paradigm.

9. Fill in the blank with the most appropriate option.
Statement: In theory of computation, abstract machines are often used in ___________ regarding computability or to analyze the complexity of an algorithm.
a) thought experiments
b) principle
c) hypothesis
d) all of the mentioned

Explanation: A thought experiment considers some hypothesis, theory or principle for the purpose of thinking through its consequences.

10. State true or false:
a) true
b) false

Explanation: In computer science, Random access machine is an abstract machine in the general class of register machines. Random access machine should not be confused with Random access memory.

Sanfoundry Global Education & Learning Series – Automata Theory.
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