Interview Questions Answers in Electrical Engineering, Power Plant Engineering

Question { 2974 }

In aircraft,why we use
400 htz equipment.and use common
earthing

Answer

Probably for earth ( ground ) fault locator ?

Is This Answer Correct ?

0 Yes

0 No

Question { 4504 }

how to calculate the current carrying capacity of a 25 & 16
kva distribution transformer.

Answer

Take pf as unity. kva= v x I/1000 .If three phase 1.732 x Vline x I /1000

Is This Answer Correct ?

1 Yes

0 No

Question { 4163 }

can a 12v dg starting battery(150 AH) be replace by 6 nos of
200AH batteries each of 2v connected in series.

Answer

It is better

Is This Answer Correct ?

4 Yes

0 No

Question { 5493 }

what is recommended breakdown voltage of transformer oil?

Answer

Minimum bdv in kv - 60 for 170kv and above class , 50 for
for 72.5 to 170 kv , 40 for below 72.5 kv

Is This Answer Correct ?

3 Yes

1 No

Question { NDFL, 6850 }

what is the relation between the grid voltage and generator
voltage how to link up generator with grid

Answer

It is better to have generator voltage slightly higher ( not exceeding 3 %) than grid voltage ,while synchronizing , to avoid leading pf on synchronization

Is This Answer Correct ?

3 Yes

1 No

Question { CTS, 4888 }

what voltage generated earth tester meter when we testing the Earth point ?

Answer

It is about 50 V AC in 0-10 ohm range and 100 V AC in 0-100 ohm range ( Waco instrument )

Is This Answer Correct ?

4 Yes

3 No

Question { 3072 }

how to calculate unit consumption on 3phase 380-415 v0lt kilowatt motor eg ( 55kw,380v,3phase 50-60hz)

Answer

Consumption in units or KWH = power in KW x time in hours

Is This Answer Correct ?

5 Yes

1 No

Question { HDFC, 10326 }

What is motor type DG starter

Answer

Priming done with a motor and not rope

Is This Answer Correct ?

2 Yes

0 No

Question { UET, 4092 }

63.5 ohm NGR is connected with our gas engine genrator running at 500 rpm, 50 hz and synched with WAPDA at 6.3 KV bus voltages, 2500A and 25KA(1 sec). can some one give me proper calculations how it comes 63.5ohm?????

Answer

Rated voltage / NGR resistance = rated current

Is This Answer Correct ?

0 Yes

1 No

Question { Orient, 4123 }

How to calculate the cross section area for a 350 m cable, motor power is 26 kw???

Answer

rho x L /A = R , R x I = voltage drop . Choose the maximum allowable voltage drop and arrive at A

Is This Answer Correct ?

4 Yes

0 No

Question { 3612 }

what happends when an isolater is operated on on-load

Answer

As you open the contacts there will be heavy arc between contacts ,intensity depending on voltage ,current and weather condition. The arc will break as the separation increases and there will be a heavy sound . Insulators in the vicinity may be damaged due the heat produced by the arc . Never try it

Is This Answer Correct ?

3 Yes

0 No

Question { 3271 }

if a train is running on a speed of 40 K MPH and crosses a individual passing by him in 48 secs who is riding a horse with a speed of 25 K MPH. what is the length of the train?

Answer

200m

Is This Answer Correct ?

1 Yes

1 No

Question { 3271 }

if a train is running on a speed of 40 K MPH and crosses a individual passing by him in 48 secs who is riding a horse with a speed of 25 K MPH. what is the length of the train?

Answer

200 m

Is This Answer Correct ?

1 Yes

1 No

Question { 3543 }

What are Directly Exited Generators?

Answer

Do you mean self - excited ?

Is This Answer Correct ?

3 Yes

0 No

Question { 2680 }

Dear,
How much ph is maintained of water electrolite used in lrs for slipring induction motor ?

Answer

Anyway more than 8 . Even 13 can be expected

Is This Answer Correct ?

1 Yes

0 No

k.prakashchandra