15) What is the power factor, if one wattmeter reads zero and other reads some positive reading in two wattmeter method of 3 phase power measurement?

16) What is the name of star point in star connection system?

17) What will be the neutral current in 3 phase-unbalanced circuits?

18) In a 3 balanced star connected system having a phase voltage of 240V calculate the line voltage in the circuit?

19) Which type of the power measurement is used for balanced and unbalanced louds in 3 phase system?