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CIE PHYSICS P4 QUESTIONS

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AndrewCedric:

--- Quote from: s16 on May 26, 2010, 04:41:21 pm ---In jun 04 d.ii) why is it 3 ?!

--- End quote ---

It is not a sine wave. Square waves have the RMS equal to peak voltage. You have to accept this at A level.
For sawtooth voltage , for example, its RMS=Vo/( square root of 3). And so on.
You can check it out at wikipedia if you want to know the detail explanation

s16:
Ok thank you I never knew about this.
Oh and could anybody please explain eddy currents to me ? I don't really get them where do they come from what do they do ... ??

Onion:

--- Quote from: s16 on May 26, 2010, 04:41:21 pm ---In jun 04 d.ii) why is it 3 ?!

--- End quote ---
Actually there is another way to think of it. First what is the rms value - its the Root Mean Square value

that means you Square all the values first (when you square - you'll get the value of 9 [both the -ve and +ve part])
then you take the Mean (mean of 9 is just 9  :D)
and last you take the Root (square root of 9 is 3 !!  ;))

s16:
What about june2009 q11.b)iii) .. I don't understand what they did :s

s16:
And q6 June 2009 also part c) please .. To do with rms .. Which I'm really confused about !

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