Please tell me the explanation and answer of following questions:

1. how many 2 state Finite automata can be drawn which accepts empty language?

2. fsm with output capability can be used to add two integers in binary representation?

3. sum of regular language and Non-regular language is regular?

4. String of 0's whose length is a perfect square is regular language?

5. If R is regular and N is non-regular ,then R+N is regular?