Ambiguous/badly-worded question. But here are answers...
The emf of each cell (or battery) remains unchanged; but within the circuit, the total emf=0 as the 2 emfs are opposed and 'cancel'.
Potential difference between the 2 positive terminals is zero.
Potential difference between the 2 negative terminals is zero
Potential difference between a positive and a negative terminal equals the emf of a single cell (or battery).
Current in circuit = 0 as to total emf=0.
Circuit reistance is the sum of the internal resistances of the two cells (or batteries) as they are in series.
All of the above.
R is zero because ideal voltage sources have no resistance. You have no resistor in this circuit.
V is zero for a variety of reasons, among them that you have a wire connecting the terminals together, and there is no resistance (and therefore no potential difference) along a conductor.
I is zero because V is zero.
If you connect two batteries with their positive terminals together and their negative terminals together, it's not a series connection. This is a parallel connection.
When 2 identical batteries are connected in series with +ve terminals together and -ve terminals together, forming a closed circuit which component (emf of cells, potential difference between cells, current in circuit, resistance in circuit) will be zero?
Thanks in advance.
