@Pinaki M., I realize this is an old thread but I thought I would shed some light on how the calculation is conducted to determine whether you have positive leverage. The positive leverage is not actually between the cap rate and the interest rate but between the cap rate and the loan constant.
The loan constant is the annual debt service divided by the loan balance. In your case of having a $880,000 loan amount with a 5% interest rate and a 15-year amortization term, the annual debt service is approximately $84,781.21. Dividing $84,781.21 by $880,000 yields a loan constant of 9.63% (OUCH!).
With your $65,000 NOI and $1.1M purchase price your cap rate is 5.91% as you mentioned.
Now, subtract the loan constant of 9.63% from the cap rate of 5.91% and you end up with negative 3.73%.
Therefore, given your financing structure, you're actually using negative leverage of 3.73% with that loan. As others alluded to, I'd look into some longer-term loans (30 year amortization) and options with lower rates. Today's loan programs are better than two years ago.
I hope this helps you and anyone else when running the numbers.