Housing loan deduction

Husband if he is only payng and showing in his business acount books

Husband will get the entire deduction under "Income from House propert" 

Husband can get the deduction if he is paying the entire loan amout for that FY

another scenario

Join property in hustand, wife name.

Principal and interest paid by husband, so I understand husband gets house loss deduction. Howere, ITR-2 ask is if property is in join name, when i says yes it asks percentage, and I put 50% each. When I put 50% in husband name, the annual value reduces to half as well and the loss increases compared to the case where ownership was put in as 100%

Case 1:

Now, I am in dilemma, if I put 100% ownership, it's facutally  incorrect since house and loan are in joint name. House loss will be = 2 lakh( rent) - 5 lakh ( interest) = 3 lakhs

Case 2:

If I put 50%, since annual value decreas to half, the loss widens.House loss = 1 Lakh (rent) - 5 lakh( interest)  = 4 lakhs.

(Omitting 30% maintenance for simplicity)

Can I claim higher loss like case 2 above ?

thanks, Sam