John Kilopascal wrote in USMA 19089: >. The power formula for DC >(P=EI) is modified when used with AC. The factor of cosine of the angle >between the current and voltage must be taken in account. If the voltage >and current are in phase, then the power is the equal to the voltage times >the current as in a DC circuit becaue the difference in angle is zero and >the cosine of zero is one. If the voltage and current are pi rad out of >phase, then the cosine of pi is zero and the power is zero too, even if we >were talking about a megamp time a megavolt
I think he meant pi/2 radians instead of pi radians. Joseph B.Reid 17 Glebe Road West Toronto M5P 1C8 TEL. 416-486-6071
