S. 271(1)(c) : Penalty-Concealment-Search-Loss return-Revised return-Violation of principle of natural justice-Faceless assessment-The conduct of the Revenue would depict a partial violation of principles of natural justice-Personal hearing was not granted-Order of penalty is set aside to pass fresh order after considering the contentions.[S. 132,143(3), 153A, 274 Art. 226]