I am having a very difficult time trying to figure out a question on my physics homework. I really am not even sure how to begin to work the problem out. Can anyone please help get me started? The question is: An autotransformer has an EMF source of 240 volts, only 20% of the autotransformer will be used. The step-up transformer is supplied with 30,000 Watts of power and has a turn ratio of 500:1. Based on the information calculate the following: voltage primary, voltage secondary, current primary, current secondary, and power secondary.