Allowing the appeal the Court held that the assessee had no other source of income except through generation and sale of power. All its receipts and expenditure related to a single activity of power generation. The interest received from the bonds issued by the Grid Corporation had a direct nexus with its essential business activity and, therefore, was income derived from interest is  eligible for deduction.(AY.2002-03, 2003-04, 2007-08 to 2009-10)