Question { CTS, 7524 }

The ratio of white balls and black balls is 1:2. If 9 gray
balls is added it becomes 2:4:3. Then what is number of
black balls ?

Answer

12

Question { Appco, 33141 }

what is the disadvantage of leading power factor...why can't
we use it (pf=0) for a long period of time?

Answer

In practically it is not possible(i.e.power factor=0).If
Theoretically power Factor=0,means there is no actual
power(true power).(i.e.only wastage of power).
i think your i question is wrong pf=0 means lagging power
factor.
there is no disadvantage of leading power factor.
if lagging power factor means more wastage of power

Question { Essar, 6007 }

what is international rules of electrical?

Answer

all are follow IEC.IEC means The International
Electrotechnical Commission is the international standards
and conformity assessment body for all fields of
electrotechnology.