3.3 A core-type transformer has a mean length of 0.6 m and a cross-section of 0.005 m2. The core is made of silicon sheet steel and has primary and secondary windings with 150 and 450 turns, respectively. The source voltage is 200 V-rms at 60 Hz. On open circuit, estimate the exciting current, (a) when the 150-turn winding is placed across the source, 450-turn winding across the load. (b) when the 450-turn winding is placed across the source, 150-turn winding across the load.