I am currently experimenting with pwer tranformers and the parameters of the experiment are 1V AC into a 120V - 6V 12VA step down transformer. Measurements are taken in input and output voltage and amps and recorded against frequency change. the secondary side has a 10kohm reistor for load. frequencies are varied from 30Hz - 30kHz. the input voltage output voltge and output amps remained similar but the input amps decreased with increading frequency --significantly ....this results in an increasing efficiency why? any ideas greatfully received