Prejudgment interest, i.e., interest as an element of, or in the nature of, damages, as permitted by the statutory and common laws of the state as of April 1, 1979, may be awarded by courts or juries in accordance with the principles of equity at any rate not in excess of a maximum effective rate of ten percent (10%) per annum; provided, that with respect to contracts subject to §47-14-103, the maximum effective rates of prejudgment interest so awarded shall be the same as set by that section for the particular category of transaction involved. In addition, contracts may expressly provide for the imposition of the same or a different rate of interest to be paid after breach or default within the limits set by §47-14-103.