(a) The proceeds of an issue of taxable bonds and the investment earnings thereon shall be used, in the manner, and to the extent specified in the ordinance or resolution providing for the issuance of the bonds, by the governmental unit issuing the bonds for a purpose specified for the issuance of bonds in the law under authority of which the bonds are issued.
(b) Notwithstanding subsection (a) of this section, invested or reinvested proceeds of an issue of taxable bonds shall be deemed to have been expended for a purpose specified for the issuance of bonds in the law under authority of which the bonds are issued if the earnings thereon and proceeds of liquidation of the investments are acquired with such proceeds, to the extent that they are:
(1) Applied to pay or service debt service on the bonds; or
(2) Applied toward such a purpose.
(c) When the bond proceeds of taxable bonds are invested or reinvested by the governmental unit in obligations permitted by this subchapter, the issuance of the taxable bonds shall be deemed to be for a public purpose, provided, the net proceeds of such investment or reinvestment, after sufficient provision is made for debt service on the bonds, are then applied to a purpose for which the governmental unit has authority to issue bonds and the governmental unit has determined upon appropriate findings of fact that such application of net proceeds is for a public purpose which the governmental unit is authorized or empowered to perform.