Electrical Engineering Interview Questions

In a 3 phase 4-wire system. For a 3.5 core cable if all loads are single phase and balanced, what will be neutral current? will it be sum of all phase currents? Or it will be zero? And if loads are unbalanced what will be neutral current?

1182

explain the functions of main isolation switches

Zesa,

1123

please I wont know how to calculate the vector group for power transformer ZNyn11 best regard.

1191

The synchronous machine excitation system explain

1218

Any formula to calculate neutral current in 3 phase 4 wire system

2033

What are IP protections used for electrical panels, JB, equipments installed in explosive zones like Petrochemicals, Oil & gas

1121

In my 3 phase 4 wire electrical system N to earth voltage is 0.08 is it ok What is standard for it ?

1468

What are the difference between normal application Transformer and Solar application Transformer?

1172

how to handle 2500 kva transformar

1061

why are transformer rating in MVA

2677

a starter used for squirrel cage induction motor?

1148

Instrument connected to a single phase supply

1167

What is the safe limit of voltage between earth and neutral in india.

2689

Power systems

1210

What is the possible cause for failure of lightning arrestors in outdoor substation under normal condition

1180

Un-Answered Questions { Electrical Engineering }

How will be the single line diagram of series trip HT breaker? how it works?

1976

Please explain, how to test vector group of tranformer(Delta y1) . Thank

1150

1394

How to calculate or formula to calculate rhe power in 2 phase system ??

897

H.t motor 6600 volt to same motor lt supply 440volt supply applyed to h.t motor to effect....

1392

how to determine the inrush current of a transformer

2032

how solar power plant energy meter multiplication factor

1531

Explain forward resistance, static resistance and dynamic resistance of a pn junction diode.

557

how to design step down 12 V, 1mA small transformer from 220 V AC? Because according to VI relation and power transfer it results bulky...

1605

how the B-H loop obtain under the static condition

1728

Why sometime AVR and sometime Booster coil is used in Alternator? what is the diferance between AVR & Booster coil due to which they are selected

2496

What are the ratings of VCB, MCB, MCCB, SF6, ACB, and OCB?

1018

TRAFO 1. WHY BREATHER IS USED. 2. WHY OIL GOES DOWN IN CONSERVATOR TANK. 3. WHY WE ARE TAKING OIL SAMPLE TAKING FROM BOTTOM OF TRANSFORMER. 4. HOW TO CHECK IR VALUE OF TRANSFORMER. 5. WHY OLTC HAVING BUCHHOLZ TRIP ONLY; WHY NO ALARM. 6. OFF LOAD TAP CHANGER OPERATION PROCEDURE. 7. TR. SHUTDOWN / ISOLATION PROCEDURE. 8. WHEN THREE TRS. IN PARALLEL, ONE TR. IS NOT SHARING THE LOAD – WHAT IS REASON AND WHAT YOU WILL DO. 9. WHY TR. HAS OLTC IN HV SIDE. 10. WHAT IS % IMPEDANCE. 11. WHY TR. RATING IN MVA. 12. WHAT IS VECTOR GROUP IN TR. 13. CONDITION FOR PARALLEL OPERATION OF TRS. 14. WHAT IS TERTIARY WINDING. WHERE IT WILL BE. 15. IF TR. TRIP ON BUCHHOLZ OR TAP CHANGER RELAY, WHAT YOU WILL DO. 16. DIFFERENCE BETWEEN OIL TEMP. AND WINDING TEMP. PROTECTION 17. HOW WINDING TEMP. IS MEASURED IN CAST RESIN TR. 18. DIFFERENT TYPES OF FAULTS IN TR. Trafo - Page-1 of 2 19. WHAT HAPPENS WHEN TR. CHARGED FROM LV. 20. WHAT WILL YOU DO IF MEGGER READING SHOWS ZERO BETWEEN LV WINDING AND EARTH. 21. CAN WE INTERCHANGE BUCHHOLZ RELAY OF MAIN TANK AND OLTC TANK. 22. IF THE LINE BETWEEN BREATHER AND CONSERVATOR TANK 23. LOCKED, WHAT WILL HAPPEN DURING LOAD CYCLE. 24. WHAT IS THE FUNCTION OF OIL SEAL IN BREATHER. 25. WHAT ARE LOCATIONS FOR BUCHHOLZ RELAY FIXED IN POWER TR. 26. WHAT ARE CHECKS IN POWER TR. DURING MAINTENANCE. 27. WHAT IS IMPORTANT WHEN WE CHECK OLTC OPERATION DURING MAINTENANCE. Trafo - Page 2 of 2

1914

what is RNG in the DG synchronizing by PLC?

1523

what is apparent poewr, reactive power, & active power?

1652