about tax pay

If you have taxable income then and only you will get benefit of exemption

if your wife does not have any source of income then how can she avail the benefit of exemption

another point source of income is in your hand not in the hands of your wife so above mentioned income will be taxable in your hand only

for amount of dedcution of Rs. 250000 I have assumed that you have availed full 150000 of 80C and other losses of house property or other dedcuction on plain reading of your query