Interview Questions Answers in Electrical Engineering

11/.433KV, 100KVA TRANSFORMER is supplied with .433KV AT
ITS PRIMARY. HOW MUCH KVA IT CAN SUPPLY

Answer

without knowing the current rating it is not possible to
find the kva.if 0.433kv is given at primary, u can find
only the secondary voltage vid the help of turns ratio.so
its not possible to find.

Is This Answer Correct ?

6 Yes

1 No

Question { 3833 }

anybody can give the voltage value for 1M ohm

Answer

please mention the current value

Is This Answer Correct ?

7 Yes

0 No

Question { 31276 }

why dc series motor has high starting torque

Answer

basically torque of dc motor mainly depends on armature
current and flux.for a dc shunt motor ,this flux is nearly
a constant but for dc series motor this flux is mainly
dependent on armature current.so torque of dc series motor
is now dependent on square of armature current. hence it
has a very high starting torque.

Is This Answer Correct ?

113 Yes

11 No

Question { 8379 }

what is working of communitator in a dc generator?

Answer

commutator mainly facilitates the collection of current
from the armature conductors and also converts the
alternating current induced in the armature conductors into
an unidirectional pulsating dc current in the external load
ckt.this is done by proper switching of current in the
right coil at right time.

Is This Answer Correct ?

7 Yes

1 No

Question { 4763 }

Hello sir
This is prakash from
bangalore i have a doubt why we have to
maintain DG power factor in the range
0.78 to 0.8
Perhaps i f it is increased means what
will happen in DG

Answer

if power factor goes beyond 0.8 (say 0.9), your dg will be
over loaded and may trip or call for frequent overhauls.

Is This Answer Correct ?

1 Yes

5 No

Question { 6371 }

what will be fault level of 11 KV , 2000 A ELECTRICAL
SYSTEM?

Answer

c.b.t, can u plz exlain how u got tat answer,coz to b frank
i donno how to calculate the fault level of an electrical
system.

Is This Answer Correct ?

0 Yes

0 No

Question { IOCL, 5498 }

Why electric traction is used ??

Answer

higher power-to-weight ratio,Electricity enables faster
acceleration and higher tractive effort on steep grades.
lack of exhaust fumes at point of use, less noise and lower
maintenance requirements of the traction units.no need to
switch between methods of traction thereby making
operations more efficient
source: wikipedia

Is This Answer Correct ?

2 Yes

2 No

Question { 7200 }

what is the operation of UPS ?
can any one answer me?

Answer

ups will be present between the equipment and power socket.
the electricity flows from socket to ups n then to
computer, battery continuosly checks the power levels and
also collects the power.when the power levels are not
within the normal parameters, ups vil connect the batteries
for compensating the lack of power.whwn the power is
restored to the normal flow,ups vil start recharging the
batteries.

Is This Answer Correct ?

5 Yes

3 No

Question { 7200 }

what is the operation of UPS ?
can any one answer me?

Answer

well ppl,everyone knows the full form of ups and tat, it
provides the back up facility.but the question posted
is "what is the OPERATION OF UPS". frankly speakin even i
dint know the answer.i surfed the net n i went thru the
following link http://www.backuphowto.info/how-calculate-
ups-battery-backup n found the answer to be quite
satisfactory.if u still think the answer is wrong,i
apologise for tat....

Is This Answer Correct ?

0 Yes

0 No

Question { L&T, 15862 }

what is looping circuit in electrical lighting circuits?

Answer

i donno whether this is the exact answer....plz check it ppl

Loop type lighting circuit
In this type, a twin and earth cable runs from the consumer
unit to each of the ceiling roses one after the other.

From each rose, another cable is run to the switch which
operates that light.

source : http://www.diyfixit.co.uk/electrics/lighting-
circuits.html

Is This Answer Correct ?

3 Yes

1 No

Question { OPTCL, 37174 }

What is the difference between ARC & SPARK?

Answer

An electric arc is an electrical breakdown of a gas which
produces an ongoing plasma discharge, resulting from a
current flowing through normally nonconductive media such
as air.A spark is triggered when the electric field
strength exceeds approximately 4–30 kV/cm—the dielectric
field strength of air.arc is continuous discharge whereas
spark is momentary.votage developed due to arc is
comparitively lower.example for natural spark is lightng
where the potential difference between cloud n grnd is very
high.

Is This Answer Correct ?

92 Yes

24 No

Question { 2872 }

which MPU register provides the address from which the next
instruction byte is to be fetch?

Answer

program counter register

Is This Answer Correct ?

3 Yes

0 No

Question { 10644 }

AC voltage only create magnetic flux in coils, but in Solenoid
coil how 24V DC volt create flux and pick the plunger

Answer

one thing i wanna make a point oer here is tat, its not tat
only ac can produce magnetic flux, even dc produces
flux.only difference is tat dc produces stationry flux
while ac produced alternating flux.without dc flux, then
there wont b dc motors....wat i gues for the answer is
tat,dc produce stationry flux n ven current flows in
solenoid coil due to some other reasons, then due to the
rotating effect developed (i.e torque),the plunger vil b
picked. the answer is juz a guez.so plz bear vid me ppl.

Is This Answer Correct ?

1 Yes

1 No

Question { L&T, 18213 }

different between grounding & earthing?

Answer

both are same.grounding is a term used in USA whereas
earthing is equivalent term of grounding used in UK.

Is This Answer Correct ?

6 Yes

15 No

Question { IIT, 8478 }

Three way plug point is there ,in that plug why we need
earth pin is bigger than compare with phase and nutral pins?

Answer

Reason of earth Pin larger in diameter than other pins in a
plug socket :-
Accidently also one can not insert earth pin in other
pins .
the above feature is for foolfroop safety & no other
reason like low restance etc

Is This Answer Correct ?

0 Yes

0 No

meenakshi