Interview Questions Answers in Electrical Engineering

Questions / { harish - greenesol }

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Answers / { harish - greenesol }

Question { 7249 }

what are the shades for mimic diagram i.e for
3.3kv,6.6kv,11kv,22kv and 33kv?
which is the IS for mimic diagram?

Answer

I KNOW ONLY FOR 11 KV - SIGNAL RED TO SHADE 537 OF IS-5

Is This Answer Correct ?

6 Yes

2 No

Question { ABB, 11558 }

difference b/w eath and neutral

Answer

EARTHING IS TO PROTECT FROM REVERSE CURRENT AND LEAKEAGE
CURRENT , AND NEAUTRAL IS USE TO COMPLEATE THE CKT.

Is This Answer Correct ?

10 Yes

2 No

Question { Coca Cola, 10691 }

WHY WE USE 4-20mA

Answer

actually for plc and for electronic systems we usually
supply in mamps. GENERALLLY FROM TRANDUCER WE USE TO TAKE
OP IN 4-20MA , for RTD also .

Is This Answer Correct ?

4 Yes

9 No

Question { 10994 }

What is the need of motor starter?

Answer

to control the speed of motor through voltage , and to
start smoothly.also some of the cases we can control the
starting current.

Is This Answer Correct ?

8 Yes

1 No

Question { 53019 }

why does chattering take place in ac contactors?
can it be avoided & what care does the manufacturer take to
eliminate this phenomenon????

Answer

chattering occurs due to many conditions:
1. due to loose contact
2. dust contents
3. new product will not get contact very quickly but after some periodic operation it will be rectified.
4. under coil rating e.t.c

so major is no 4 & 2 this shall be taken care by manufacturer

Is This Answer Correct ?

13 Yes

11 No

Question { Wheels India, 16869 }

What power factor maintain you maintain at u r organisation

Answer

and same here to, we maintain of power factor of .8 or .9,
must close to that

Is This Answer Correct ?

5 Yes

3 No

Question { 13451 }

how we select fuse rating for motor?

Answer

fuse rating is selected depending upon the full load current of the motor , generally 1.5 times higher then the full load current.

Is This Answer Correct ?

16 Yes

2 No

Question { 6806 }

can i have the methods of speed controls for 3 phase AC
MOTORS.

Answer

more then that above formula is there any thing

Is This Answer Correct ?

2 Yes

2 No

Question { 4700 }

800a siemens vcb in our company can not be closed electrcally
an mechanicaly cc and oc coils are found ok. why?

Answer

please check the BREAKER FUTURE INTERLOCKS ( LOOPS) MISSING IN THE CIRCUITS.

Is This Answer Correct ?

2 Yes

0 No

Question { HBL Power Systems, 7058 }

what is motor

Answer

motor is a operating machine in which it required input of electrical energy , to provide an mechanical output.

Is This Answer Correct ?

13 Yes

1 No

Question { 9673 }

how did the differential relay work to protect the power
transformer

Answer

Differential relay will operate with differential current between phase and neautral of the generator. it is operated with CT CONNECTIONS

Is This Answer Correct ?

2 Yes

7 No

Question { 5501 }

why do we have 230v a.c. as general voltage for domestic
supply rather than others?

Answer

GENERALLY ALL THE HOME APPLIANCES ARE MADE FOR SINGLE PHASE SUPPLY WHICH IS 230 V SUCH THAT WE WILL HAVE 230 V . AND SOME DOMESTIC WILL HAVE 415 ALSO FOR MOTORS ETC.

Is This Answer Correct ?

4 Yes

3 No

Question { 11333 }

What do you mean by class of CTs and what is the meaning of
cl 1.0, cl5P10, cl 10P10 CTs?

Answer

actually cl is acuracy , means in what percent accuracy, cl 1, 0.5 is for metring purpose , and cl 5p 10 , ps , 10p10 is all for protection means for relay out put , means 5 % accuracy and 10 % accuracy

Is This Answer Correct ?

0 Yes

2 No