High voltage input question?

A step up transformer with an input voltage of 240 V?

• Background info. Anode and cathode in an xrya tube with a potential difference of 120 kv provided by a three phase fully rectified circuit. The tube current is 80mA. The filament carries a current of 3.5 A. So those values are meant to help with the question... the 120kv tube voltage is created by a step up transformer with an input voltage of 240 V. What is its turns ratio. Assuming tht the transforner and rectification are 95% efficient how much current flows through the primary coil of the transformer? I know its a long question but I would appreciate any help, even if it just which equations to use, or a step by step of how to go about getting the right answer... Thanks :-)

• Answer:

  120kv=1,20000V ,.Ideal ratio is 1000:2, but there are other factors to be considered such as diameter of the coil(CS area),Core properties,copper and iron losses etc..