turing machine

Question

can we have a turing machine which has only one state ?

or

the minimum number of state for  a turing machine is 2?

Comments

i think its 2 states.

reason: final state of tuning mechine cannot have any transition, not even loops.

To accept a null language we need a transition on Blank symbol 'B', which cannot be placed on final state itself.

hence 2 states are required.

Correct me if i am wrong

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Who said every turing machine needs a final state?
Ever heard of a transducer?

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@Sasta_yoda

https://www.seas.upenn.edu/~cit596/notes/dave/turing7.html

here it says it halts on a final state.

can you provide a link that says otherwise?

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Do you have a link which says every TM needs a FINAL STATE? Just so you know the question was simple, Does a TM always need two states? The answer is simple, no it does not ! 
I can always define a TM which does nothing but moves towards right infinitely in the same state on the Blank symbol. 
Please read carefully what is being asked, before wasting everybody else's time. :) 
@OneZero

Answer 1

There is no such restriction, as long as the TM has a initial state, transition function, input alphabet, set of all states, tape alphabet, a blank symbol, and a set of final states. It will be always be a TM.
Note: the set of final states can always be PHI or null. But there will always be an initial state.
PS: If you found the answer to be helpful, please consider upvoting !

Answer 2

A TM needs to have at least two states - an accepting state and a rejecting state.

The accepting and rejecting states must be distinct because the machine cannot simultaneously accept and reject. Therefore, there must be at least two states.

With a single state, you can not accept anything.

A Turing Machine's transition looks like (X, Y , R/L). With single state you will specify at least one transition, now that transition will surely contain R/L, therefore Turing Machine will never stop it will either keep moving right or keep moving left or oscillate b/w left and right.

Refer: 

https://gateoverflow.in/172305/turing-machines

https://cs.stackexchange.com/questions/86538/why-does-a-turing-machine-need-at-least-two-states

http://cobweb.cs.uga.edu/~potter/theory/4_Turing_Machines1.pdf

https://en.wikipedia.org/wiki/Turing_machine

Answer 3

No. A Turing machine must contain at least two states: an accept state and a reject state. Because
being in either of these states halts the computation, a different start state would be necessary in
order for the TM to read any input whatsoever.