Answer / imran qureshi

Rating of any electric equipment gives information about
the maximum limit of parameters upto which the losses are
considerable and not affect its operation.
In a transformer, the effecting parameters
are voltage and current only and not frequency.Because
operating frequency in a transformer is constant.
Core loss is due to the voltage and copper
loss is due to current.
KVA=1000*voltage*current
while, KW =1000*voltage*curret*power factor
(power factor depends on frequency)

Answer / ashish kumar

Kw = 1000*v* I* Pf
KVA = 1000* v* I

here the only difference is power factor.and power factor
dedends upon nature of load i.e. weither the load is
resistive, inductive or capacitive..................becouse
the nature of the load is not pre known to us that is why
the power factor is not predetermined that is why we rate
transformers and diesel generators in KVA.

Answer / sandeep

In transformer
frequency is constant
d formula for
KVA=1000*Voltage*curent
and
kw=1000*voltage*current*power
factor the power factor
depends on frequency
but the frequency is
constant in transformer

Answer / anil

as transformer is a appliance used to transform the
electrical parameter like Voltage and current. power factor
is not included while calculating rating of transformer.

100 MVA 3-phase alternator with earthed neutral has a reactance of 5 ohms per phase. what will be the fault MVA of generator.

0 Answers  

---

please explian how may types of maintenance works.

4 Answers   HP,

---

different between circuit breaker & switchgear & relays

6 Answers   EFS,

---

In a synchronous machine if the field axis is ahead of the armature field axis then the machine is ?

1 Answers  

---

what is power factor?

8 Answers   Adani, Blue Star, Power Control,

---

Which thing is maximum in RLC circuit at resonance a)power consumption b)inductive current c)capacitive voltage

0 Answers  

---

what type of relay has to be used for tripping the circuit from mains when a fault occur in a machine

3 Answers  

---

how does high earth to neutral voltage affects electronic circuit?

0 Answers  

---

Is there any capacitor in 3-phase IM?why,xplain.

2 Answers  

---

In synchronous generators field is rotor and armature is stator.Can we take the output at the rotor in case of synchronous generator by the dc excitation on the stator?

2 Answers  

---

what will be efficient rating of ac motor to lift a 10 kg wt of stone to 10 meter height with input 220V AC 50 Hz frequency???

1 Answers  

---

all interview questions with answers of ntpc (2000-2009

0 Answers   Hetero, NTPC,

---