Ground is connected to phase A on previously ungrounded 480V wye system. What is the line voltage at phase C?
My answer: Question implies 480V line-line voltage. Having phase A grounded on a previously ungrounded system just creates a floating ground. Therefore phase C's line voltage is...
If you have a way of sending the formulas I would be intereted in them too. I have started my own but it would be nice to see a formula sheet that was used to pass the test :)