<s>[INST] Article 286 of Indian Constitution [/INST] Restrictions as to imposition of tax on the sale or purchase of goods
(1) No law of a State shall impose, or authorise the imposition of, a tax on the sale or purchase of goods where such sale or purchase takes place
(a) outside the State; or
(b) in the course of the import of the goods into, or export of the goods out of, the territory of India
(2) Parliament may by law formulate principles for determining when a sale or purchase of goods takes place in any of the ways mentioned in clause ( 1 )
(3) Any law of a State shall, in so far as it imposes, or authorises the imposition of,
(a) a tax on the sale or purchase of goods declared by Parliament by law to be of special importance in inter State trade or commerce; or
(b) a tax on the sale or purchase of goods, being a tax of the nature referred to in sub clause (b), sub clause (c) or sub clause (d) of clause 29 A of Article 366, be subject to such restrictions and conditions in regard to the system of levy, rates and other incidents of the tax as Parliament may by law specify"
Article 287 of Indian Constitution,"Exemption from taxes on electricity Save in so far as Parliament may by law otherwise provide, no law of a State shall impose, or authorise the imposition of, a tax on the consumption or sale of electricity (whether produced by a Government or other persons) which is
(a) consumed by the Government of India, or sold to the Government of India for consumption by that Government; or
(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"," </s>