Figure B3 displays the dimensions of a 50 Hz step-down transformer. The core has a cross-sectional area of 2 cm x 2 cm and is constructed of laminated silicon stell with a relative permeability of 1500 and a saturation transformer's nameplate specifies an apparent power of 250 VA, a primary voltage of 220 , and a secondary voltage of 12 V. During the open circuit test, an input current of 0.01 A was measured. The input power was deemed negligible and disregarded