Where, in the course of any proceeding in connection with the assessment of tax under Part 10, the Deputy Commissioner of Taxes is satisfied that any person has—

(a) without reasonable cause, failed to pay advance tax as required by section 154; or

(b) furnished under section 155 any estimate of tax payable by him which he knew, or had reason to believe, to be untrue,

then he may impose upon such a person a penalty of a sum not exceeding
the amount by which the tax actually paid by him falls short of the amount that should have been paid.