4.3. The number of turns in the primary and the secondary of an ideal trans- former are 200 and 500, respectively. The transformer is rated at 10 kVA, 250 V, and 60 Hz on the primary side. The cross-sectional area of the core is 40 cm². If the transformer is operating at full load with a power factor of 0.8 lagging, determine (a) the effective flux density in the core, (b) the voltage rating of the secondary, (c) the primary and secondary winding currents, and (d) the load impedance on the secondary side and as viewed from the primary side.