Household electrical voltages are typically quoted as either 110 V, 115 V. or 120 V However, these values do not represent the peak ac voltage. Rather. they represent what is known as the root mean square of the voltage. defined as

Where T = the period of the waveform, Vm is the peak voltage, and w = the waveform frequency (f = 60 Hz in North America).

(a) Perform the indicated integration, and show that for a sinusoidal voltage.

(b) Compute the pek voltages corresponding to the rms voltages of 110,115. And 120V.

Vm= V cos (wt) dt V V m 2