Question { 24636 }

1. What is the difference between ac induction motor
and ac synchronous motor?

Answer

Above answers are ok.

If you want more, get diploma 4th sem Electrical machines 2
book.
You have get clear knowledge about the motor

Question { Reliance, 25600 }

How to calculated capacitor rating both HT

Answer

capacitance of the capacitor is mentioned in KVAR.

Formula : KVAR = KW*tan@

FOR tan@, First note the power factor & KW without
connecting capacitor.
The noted power factor is in cos@.Convert the cos@ value in
tan@.
for ex. If power factor is 0.6, KW = 200
cos@ = 0.6
cos-1 (0.6) = 53.1
tan (53.1) = 1.333
200*1.333 = 266.6 KVAR
if you use 266 KVAR capacitor, Then the power factor
improves to unity (1.000).

Question { 8924 }

what is ohms law?

Answer

the previous answer is absolutely correct.
ohms law is defines the relation between resistance,current
and pottential difference.
OHMs LAW : At a constant temperature potential difference
is proportional to the current flowing through the
conductor and inversely proprtional to the resistance.

Question { 11986 }

If we connect the capacitor banks for DG set for maintainig
the power factor, it will effect to alternator
windings??????????

Answer

The cable between terminal to capacitor will burn if we
connect additional (external) capcitor.

Question { 26990 }

How can calculate the efficency of the rectifier. input
240V AC, current 5 amps,P.F 0.98, Output is 54 V DC,62.6 A.

Answer

Dear Mr.swapnil,

you have given the formula as P=VI*PF for both
input and output.
You should remember that the pf is not considered in the
DC (output of rectifier).

MY PROBLEM IS, OUTPUT POWER OF THE RECTIFIER IS GREATER
THAN INPUT. SO THE EFFICIENCY IS MORE THAN 100%. But the
efficiency must be with in 100%.

Any way thank you for your answer.

Question { Cushman Wakefield, 56385 }

how to calculate the battery Ah? what is the formula.

Answer

AH = Amps x hours.
If we use 15A from a battery of 1000AH, then we use upto
66 hours. (i.e., 66x15= 990 ). Th duration of usage is
decreased according to high amps.

Question { Cushman Wakefield, 56385 }

how to calculate the battery Ah? what is the formula.

Answer

The question is about the battery. The battery had only DC
voltage source.
In dc, no power factor.

Question { Emerson, 12963 }

Any one Give me formula for to increse the power factor,
0.8 to 0.95, How much the KVAr Required

Answer

pls verify the whole questions. i just already give the
formula with examples.