mind blockage - another electricity query

[Susan John]

This is a question sent to me by one of my students regarding last year's electricity level 3 paper. Can someone throw some light on this query. Thanks

1 have just been looking at the 2007 NCEA electricity paper and I have a question about it. I hope you don't mind responding to questions by email. I

My query is about question 2. l), which asks you to find the maximum energy stored in the capacitor at resonance. To do this you need to know the maximum voltage across the capacitor. The answers suggest that the value of the maximum voltage is XI, where I = the current in the circuit at resonance as given by I = V/R. It was my understanding, however, that the formula I = V/R gives the RMS current only - the maximum current would be greater. Presumably, then, the maximum voltage across the capacitor would also be greater, and this would give a greater maximum energy? Clearly I am making a mistake in my reasoning somewhere but I am not quite sure where!

I was under the impression that the value for current, 0.833, is the RMS current through the resistor, and that the current would have to be higher than that at some point.  At that moment, then, the energy stored in the inductor would be greater than the value calculated, sinceEp = 0.5LI^2. Am I misunderstanding the meaning of the value 0.833 for current?
Many thanks for this.

Cheers
Susan
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