Electrical Engineering Interview Questions

critically criticize the application of ring main unit in power system

98

why i can not use thimble on capacitor duty contactor

99

Make a list of materials and layout diagram for a 35hp motor, to be wired at 35meter away from the MDB in a chemical factory.

94

Draw SLD for a panel has 500A Bus Bar rating, with 4 outgoing, each is 80 A (load current), showing the transformer and capacitor bank rating.

60

Draw SLD feeding from the SS up to distribution board of the load, calculate cable size, breaker sizes, and meter for the following case: Ground Floor: electric room, pump room, 5 shops, each is 15 KW First Floor: 5 shops, each is 15 KW Second Floor: showroom 30 KW Service Loads: water pump 3 KW (3ph) , fire pump 3 KW (3ph), and one DB service 12 KW (3ph).

HMK,

160

Draw an S.L.D of the main panel for a hospital, showing meter position. Essential loads are: 1) Equipment load 100 KW 2) Critical load 500 KW 3) Life AID Safety load 400 KW 4) NON-Essential load 200 KW 5) Other service loads 200 KW Calculate and suggest the size of the transformer, size of main cable, capacitor bank, and calculate the capacity of an emergency load having above first three mentioned loads is supplied by an emergency generator.

HMK,

113

what are the disadvantages of low power factor

HMK,

107

how can we Increase the Value Of Frequency in electric circuits

HMK,

136

Give accurate definitions for these electric terms: Inductor Inductance Inductive Induction Reactance Reactive Esam Baraka ٢١ ساعة

HMK,

150

how to calculate short circuit current for the busbar

HMK,

138

What is main purpose of chock coil and starter in florescent tube ?

254

What is the comparison between 30mA DP RCCB and 100mA DP RCCB and can replace it against 63A MCB

165

7. A resistance of 30 ohm is connected across 240v supply. If a resistance R ohm is connected in parallel with 30ohm resistor across the same supply, the current drawn becomes triple of original one The unknown resistor R is

336

What is duty cycle for HT motors? How many start permitted if mentioned as 01 for hot and 02 for cold per duty cycle?

GVK,

252

Purpose of providing neutral isolation panel for parallel operation of diesel generator

207

Un-Answered Questions { Electrical Engineering }

two phases with neutral supply can be taken in 3C X 10 sq.mm cable .

227

What test must you do before powering up a circuit that you have been working on?

705

following are the questions asked in interviews: 1) Considering the short circuit fault, which switchgear is preferable, SFU OR MCCB? Which operates faster? whicg one is popular in Indian Market and why? 2)Define SCPD. What is type2 coodination? 3)Why the contactor rating is higher for the fuseless selection than for fuse selection? whether the ratinf of SFU or MCCB remains the same in both the cases? 4)If the HP rating is known then can you calculate the ratings of L.V Switchgear(SFU/MCCB, contactor, OLR) without using the selection chart?

941

Power Factor Correction Panel (Manual & Automatic)

799

how do we calculate length of starting time and repeated starting of a direct online starter?

800

For refrigerators the motor current is raised beyond its rating on both conditions when the voltage of the system is more(say 270v) than the rated voltage(220v) as well as when the voltage of system is less(say 160v) than normal voltageof 220v, why explain?

754

How many different speeds can be obtained in cascade control of two induction motors?

856

direction of tarbine& genrator

819

why it is not advisable to run low rating (19KVA) DG sets in parallel for long durations even though they are provided with droop ckts (QDC)

718

how does this job compare with others you have aplied for?

533

we can run 2phase as 3phase .what will be the differnce with respect to phase angle, power, current between the two modes

882

What is hipot test procedure?

185

Dear Sir/Madam, I have one questions we have three steam turbines and one Gas turbine and our industry linked with the public network, we have protection system one of the protection is reverse power we can export just four MW only i would like to ask about how to calculate the reverse power. Thank you in advance best regards

877

take 100kva DTR( delta/wye ), what ll happen if we connect 11kv to LT side instead of connecting to HT side? will the DTR behave as a step up transformer or something else????

1041

we have require a Motor (1500kW, 6.6kV, 50Hz) which shall operate at 1500rpm during 30min and after it shall run on 500rpm during 15min. The same cycle shall be repetitive during the whole working days. Which method is best and economic to achieve such type of task. VFD, VVFD, Pole changing motor etc.

716