Interview Questions Answers in Electrical Engineering

Questions / { manan bhatt }

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Answers / { manan bhatt }

what happend if we remove dc exciter
from moving
machine..: gg

Answer

if we remove dc exciter from running machine then due to
absence of rotational energy, machine will stop but will
take some time for remaining kinetic energy of rotor.

Is This Answer Correct ?

0 Yes

0 No

Question { 4353 }

why fan consume constant power even when we increase or
decrease its circuit resistance through speed regulator???

Answer

for fans with old resistive regulators,
total power consumed = heat loss at regulator + fan motor
consumption.
so by setting any speed that much amount of R will introduced
and produce heat loss and remaining will produce motor power.

If electronic regulators are used regulator loss can be
decreased by decreasing speed of fan.

Is This Answer Correct ?

2 Yes

0 No

Question { 4353 }

why fan consume constant power even when we increase or
decrease its circuit resistance through speed regulator???

Answer

Is This Answer Correct ?

3 Yes

0 No

Question { ICSA, 6043 }

up to what extwnt of voltage the celing fan works?

Answer

voltage should not be less than rated voltage ever for any
motor.
if for a few time over voltage of 10% tolerance is there it is
okay bcoz motor winding is capable to handle / sustain 155%
overload (or 255% full load) for few seconds

but for a safe operation rated voltage must be given.

Is This Answer Correct ?

1 Yes

1 No

Question { ICSA, 6043 }

up to what extwnt of voltage the celing fan works?

Answer

Is This Answer Correct ?

0 Yes

1 No

Question { ABB, 7812 }

What it the purpose of parallel phasing transfomers??

Answer

for achieving reliable and continuous operation.
when on 1 transformer load is 200 MW
and additional requirement is another 50 MW,
then instead of replacing 200 MW transformer it is economical
to parallel them with 200 MW || 50 MW

same principle is every where in india and across the world of
INTER CONNECTION!!

Is This Answer Correct ?

10 Yes

4 No

Question { ABB, 7812 }

What it the purpose of parallel phasing transfomers??

Answer

Is This Answer Correct ?

2 Yes

5 No

Question { Suzlon, 7741 }

what is HI POT test

Answer

it is HIgh POTential test which is generally done on power
transformers to check their capacity in various electrical
terms.

Is This Answer Correct ?

0 Yes

6 No

Question { Suzlon, 7741 }

what is HI POT test

Answer

it is HIgh POTential test which is generally done on power
transformers to check their capacity in various electrical
terms.

Is This Answer Correct ?

1 Yes

4 No

Question { TCS, 5677 }

what is the
size of trasmission conducatar

Answer

various types of material used as per requirement like AAAC,
ACSR, ACSS etc.
by calculating per phase current (which is smaller value)
with 33/66/132 kV line, its impedance is calculated first
and then simply according to ohm's law,

size of conductor:

V/I = (resistivity * length)/ (area of cond.)

thus area and diameter can be calculated. on internet
standard tables for size of cond is available.

Is This Answer Correct ?

7 Yes

1 No

Question { TCS, 5677 }

what is the
size of trasmission conducatar

Answer

Is This Answer Correct ?

3 Yes

0 No