Answer Posted / owais

as a transformer is a static device,the only loss in it are
copper loss & core loss.hence its efficiency is highest
among all electrical machines.its efficiency is generally
greater than 95%.
while an induction motor is a rotating device.hence
mechanical losses are also included here.its efficiency is
generally more than 70%.

how to calculate the torque of a motor?

2184

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what is the control circuit for operating the clean room air shower

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what is earthing transformer? draw the winding dia.of earthing transformer.

1767

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How to know Resistance and Reactance value of main and aux winding of single phase capacitor start capacitor run induction motor to find capacitor value?

2098

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Zone of protection and tripping scheme of arc protection relay.

1929

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In which working principal temperature transmitter work.explain in detailed.

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sir my exam is on 19/6/2013 under electrical branch pls send me sample aptitude questions as well as sample technical questions for jindal steel and power company

2231

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Define corner frequency?

1265

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Why High voltage are generate noise ?

1580

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DEAR SIR,I GOT THE CALL LETTER FROM RRB, SECUNDERABD AS A JE-II SO PLEASE PROVIDE ME SOME MODEL QUESTION AND ANSWER PAPERS AND LAST YEAR QUESTION PAPERS

2087

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what will happen when the dc supply is given to the capacitor?

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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

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How to calculate cable rating for 3 phase supply?

2247

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Define bibo stability.

1123

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Which contains in POLE ASSEMBLY of a 11KV Kirloskar-make SF6 (Model No-FP620A12)? Will u clarify with drawing?

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