(b)consumed in the construction, maintenance or operation of any railway by the Government of India or a railway company operating that railway, or sold to that Government or any such railway company for consumption in the construction, maintenance or operation of any railway, and any such law imposing, or authorising the imposition of, a tax on the sale of electricity shall secure that the price of electricity sold to the Government of India for consumption by that Government, or to any such railway company as aforesaid for consumption in the construction, maintenance or operation of any railway, shall be less by the amount of the tax than the price charged to other consumers of a substantial quantity of electricity.
