SSC JE Electrical 2018 with solution SET-1
A delta connected 3-phase circuit has three resistance of 36 Ohms in each phase. What is the value of per phase resistance (in ohms) of the equivalent star connected circuit?
It means that the efficiency is maximum at a load when the copper-loss (variable loss) equals the core-loss (constant loss). Thus for maximum efficiency Copper loss(Variable loss) = Core loss(constant loss) Core loss = 450 Watt = Copper loss Cooper loss = 450 Watt