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# Physics/Electricity Help

Question
If A standard electrical outlet provides a 120-Hz sinewave. Would the average voltage be 108.08616?if the peak to peak voltage is 339.36

The "average" voltage, called the RMS [root-mean-square] voltage is the DC equivalent voltage that can do the same amount of work as a particular AC voltage and is calculated from:
Vrms=Vpeak/sqrt2=339.36/sqrt2=239.96 Volts
To get this value you square the peak voltage, divide by 2 to get the average and then take the square root to get the RMS DC equivalent voltage.

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#### James J. Kovalcin

##### Expertise

I am teaching or have taught AP physics B and C [calculus based mechanics & electricity and magnetism] as well as Lab Physics for college bound students. I have a BS in Physics from the University of Pittsburgh and a Master of Arts in Teaching from same. I have been teaching physics for 34 years. I am constantly updating my skills and have a particular interest in modern physics topics.