-
Spark Plug
When the power supply cable got sparked, it gets burnt or caches fire then explain why the spark plug in our automobiles never get burnt or catch fire even it spark's?
ravs42
- Aug 6th, 2010
Generally in automobiles we have an alternator that produces ample AC supply that is converted to 12V DC supply via the help of rectifiers and regulated IC usage. The 12V is then feed to the batterri...
-
Fan Condensers
Why condensers are used in fans?
veerateja
- Jan 28th, 2011
Fan condenser is just used to create starting torque by increasing the current lead through the starting winding ,after started running of 1-phase motor we can remove capacitor even after removing the...
shafialuva
- Sep 15th, 2010
The most common motor used in a normal household electric fan is a single-phase induction motor. When first switched on such a motor needs to use a "starter" winding, in addition to its ma...
-
Potential Transformers Applications
What are the applications of potential transformers other than metering and under voltage protection?
Raman Jain
- Dec 29th, 2010
There are numerous applications of Potential Transformers .1. For Metering Purpose.2. Required for Synchronisation of Feeders / Generator with Grid.3. For Feed back of AVR.4. Distance Protection of fe...
ripago
- Nov 28th, 2010
1. Over/Under Freq. Protection2. Syncrhonizing Generator to Grid.3. If you don't have spare of PMG then you can use this PT for AC Power supply to the excitation Unit of your own Genarator.
-
Transformer Secondary Voltage
Why is it that the secondary voltage of a step-up transformer is lesser than the primary voltage of a distribution transformer?
Jai Pradeep
- Mar 13th, 2011
The primary voltage of a distribution transformer decreases due to increase in length of the conductor between step-up and distribution transformer.
-
Capacitor bank
what is capacitor bank. Where it is used & why it is used
-
-
-
Electric motor start-up
Why there is a fivefold increase in a current at electric motor start-up?
eng: ahmed gharieb
- Dec 5th, 2011
Every thing in the first being hard but with time it get better. The IM is one of this thing, as in the start n=0 so that the equivalent cct of IM
exactly as before
Thanksbittu123
- Nov 8th, 2011
If You may be talking about DC motor, here is the explanation........ current through rotor is given by i=(V-E)/R. But during starting no emf is induced, E=0, So, i= (V-0)/R must be greater than if ...
-
Why there is series of resistors connected to pressure coil of watt meter?
soomnath paul
- Feb 2nd, 2013
High resistance is connected in order to make the voltage appeared across the pressure coil in phase with the applied one.
mahmoudp1
- May 1st, 2012
We connect more resistance in series to make the total resistance is high so that it wont absorb any power (amperes) for the circuit so i wont affect on the true reading and also the series coil to me...
-
Car alternator is a 3 phase generator.
In the car alternator is a 3 phase generator and rectified instead of using dc generator.
Why ac alternator is better than dc generator in any car?ripplenwinder
- Dec 11th, 2013
No! 3 phase has no rectifier or voltage regulator a car alternator does. DC the voltage and current are suppose to be 180 degrees out of phase from one another or so most people think. Current can go ...
suryatejreddy
- Apr 12th, 2013
DC generator although produces a.c,it must be converted to d.c by rectifiers in order to store in the batteries and to it supply must be dc,so in cars instead dc generators alternators are used.
-
Transformer with current source
Can the transformer be operated on current source instead of voltage source ??if ,, what will happen ?
-
3Phase rectified to single phase
If I got a 380v 3-phase supply and I want to rectify it with thyristors to single phase how much voltage will I get ?What is the relationship?thanks
SGhosh
- May 15th, 2012
The dc output of the full wave rectifier is average value the amplitude of the sine wave. In short multiply the r.m.s value of the ac input voltage by its form factor (1.11 in case of pure sine wave) ...
mahmoudp1
- May 15th, 2012
I know the output will be dc my question is how much dc voltage will be the output
-
Kva & kw
What is the relation between kva &kw
rajender
- Nov 5th, 2012
Apparent power(KVA) is the total power from the supply, active power(KW) is the usefull power at load.
reena upadhyay
- Nov 4th, 2012
Apparent p(S)=active p(P)+reactive p(Q)
s=kva=i*v
p=i*vcos@=i*V power factor=s*power factor -
Alternators
Why do not we use salient pole alternators in thermal power stations?
umeshprabhu
- Mar 11th, 2013
The Salient pole alternator because of its large diameter and short axial length takes more time to complete one revolution for a pair of poles under a coil, so the frequency of induced emf which is p...
cmallick1201
- Jan 8th, 2013
Salient pole rotor has larger diameter than cylindrical rotor. In thermal power plant rotor should rotate in high speed so that salient pole will unstable due to larger diameter so that we cant use salient pole in thermal power plant.
-
-
Electrical Machines
Why we are preferring 4 pole alternator in the production of electric power instead of 2 pole alternator ?
-
Return Neutral
in ac circuit what is return neutral , When its happenng & why ......
-
Operating range of voltage and current?
What is the operating range of voltage and current in grid supply in india?
priyank333
- May 10th, 2015
It depends of which ever load would applied & based on that it could supplied through source with that voltage & current with regulation.
TAPAS MOHANTY
- May 5th, 2015
The voltage can deviate in between +6 to -6 from its rated value.
-
Multi User OS
Which of the following options relate to a Multi User OS?
UNIX
Windows
Mac
All of the mentioned options
-
Poor performance for user programs
What percentage of system overhead will not result in poor performance for user programs?
>10%
>20%
Electrical Engineering Interview Questions
Ans