Interest under section 234

Interest Under section 234A, 234B, 234C are equally applicable for all assessees, whether its salaried or industrial assessee.  Interest u/s 234A is leviable @ 1% per month when the ITR is not filed within the due date of filing of return. Interest u/s 234B is leviable when the total advance tax deposited during the year falls short of 90% of actual tax liability. This is also payable  @ 1%Pm on the amount that falls short. 234C is applicable when there is a default in payment of installments of advance tax at the time prescribed under section and amount shortfalls from the prescribed %age. 234C is leviable @ 1% per month for the period for which the installment was remain unpaid.  If you want detailed procedures on 234A, B and C then refer to any latest Income tax book or ready recknor for this purpose.

thanx tarun

is Interest under section 234 DISALLOED  EXPENSE?

(IS IT A PENALTY ?)

IS IT MENTIONED IN THE ACT /NOTIFICATION

THANKS IN ADVANCE