wich one of the following a.c values has the same heating effect as the equivalent d.c value


A. effective value
B. average value
c. peak value
d. peak-to-peak value

 

It is P=VAcos(Pi)
Called as True power

 

cheers for that answer

 

An Rms value has the same heating effect as the equivalent d.c value.
http://www.kpsec.freeuk.com/acdc.htm
search for RMS on the above site.
Rms is a type of average value of AC calculated over one cycle.

True power is something else..It is the active power provided to a load.

 

I was looking for RMS, and didn't see it in the choice list. It varies acording to waveform, but for a sine wave it is 1/square root (2). 120VAC is an RMS value, the peak to peak value would be 120 VAC * Square root(2) * 2, or 336V P-P. The 2 is in the equation because without it we would be talking peak voltage, or one side of the sine wave only.

 

It is P=VAcos(Pi)
Called as True power

Last time I checked, cos(pi) was negative one... Effective (aka RMS) value is peak*sqrt(2), as has already been noted.

 

A Root Mean Square (RMS) voltage gives the same heating effect as a DC voltage of the same value.

 

RMS = effective.

After all,

The most common way of specifying the amount of alternating current is by stating it's effective, or rms, value. The effective value of an alternating current is that value that produces the same heat in a resistive circuit as a direct current of the same value.
---Electricity, Principles and Applications, Fowler, Sixth Edition

It may be said that the effective value of an ac is its heating value. The peak and effective values are the same for any unvarying dc.
---Electronics Communications, Shrader, Sixth Edition