Section 2(9) defines 'deficiency of profits ' as follows: (9) "deficiency of profits" means "(i) where profits have been made in any chargeable accounting period, the amount by which such profits fall short of the stand ard profits; (ii) where a loss has been made in any charge able accounting period, the amount of the loss added to the amount of the standard profits;" Section 4 defines 'charge of tax ' as follows: "Charge of tax" ( 1 ) Subject to the provi sions of this Act, there shall in respect of any business to which this Act applies, be charged, levied and paid on the amount by which the profits during any chargeable ac counting period exceed the standard profits a tax (in this Act referred to as "excess prof its tax") which shall, in respect of any chargeable accounting period ending on or before the 31st day of March, 1941, be equal to fifty per cent, of that excess and shall, in respect of any chargeable accounting period beginning after that date, be equal to such percentage of that excess as may be fixed by the annual Finance Act; Provided that any profits which are, under the provisions of sub section (3) of section 4 of the Indian Incometax Act, 1922, exempt from income tax, and all profits from any business of life insurance shall be total ly exempt from excess profits tax under this Act.