Electrical Engineering Interview Questions

no..commutator is not present in brushless exciter..

Brush are used in low rating alternators to prevent huge sparking in high rating alternators the armature winding is fixed on stator.

Earthing actually means to,if there is an excessive voltage(not current) flowing in a power system,for the protection purpose it is connected to the earth with a help of rod,or by some other metals,so...

Grounding is provided for the safety of the equipment,while earthing is provided for the safety of human beings.

High resistance is connected in order to make the voltage appeared across the pressure coil in phase with the applied one.

We connect more resistance in series to make the total resistance is high so that it wont absorb any power (amperes) for the circuit so i wont affect on the true reading and also the series coil to me...

In case of an ideal current source , it will deliver same current irrespective of the load connected to the secondary terminals thus proper transformation will not take place in order to maintain constant flux.

I assume that by current source you mean constant current source. In such case the primary and secondary voltage of the transformer will depend on the impedance of the transformer and the load. The lo...

Modulation methods used because of when I need to transmit signal with low frequency it need long antenna as frequency inverse proportion with wave length and Wave length is in direct proportion with ...

It is the device which is used to measure the flow. Flow may be such as; mechanical optical, turbine, thermal, ultrasonic, vortex and electromagnet.

Meter used to measure the flow (of liquids)

Maybe I wasnt clear on my first answer, if you have two 3 phase vibrators on say a ore feed bin they both operate in different direction ( normally indicated) the wiring connection is different how e...

both motors direction is same only the counter weight mounted on shaft its angle changes. if opposite direction motor connection done then it will break foundation.

Any shaft of the rotor is connect with a prime mover which is able to move the rotor greater than its synchronous speed, then negative slip can be maintained.

In AC, phase is present but in DC, negative and positive terminal is present.

Alternating current which magnitude change with time and D.C is magnitude dose not change with time its always same.

It is a proven fact that Capacitor banks cause an a.c. humm on copper telephone lines. In some cases, power companies have agreed to remove the capacitor banks when they caused this problem in entire neighborhoods. This was discovered by Bell Labs Noise mitigation experts many years ago.

capacitor banks are basically used for power factor improvement. they are used by companies distributing power, due to induction load at homes and industries, power factor lags and to correct it and b...

You create a low-impedance path by bonding the metal parts of the electrical system and the grounded (neutral) conductor. You can achieve a touch potential of < 50v by reducing the resistance between...

Earth Grounding Conductor (EGC) size should not be less than 25 percent of the capacity of the phase conductors or the over-current device. For rating or setting of automatic overcurrent device not ex...

Simply change the phase sequence of any two wire.

By changing phase sequence that is known as plugging.

To reduce the fault level.

Isolation name suggest it gives the isolation means which makes insulation to protect any devices.

If your cable is 300mm, grounding conductor size is one core of cable, which cable is used to connected the equipment.

Transformer rating in KVA instead of KW since its iron loss depends on voltage and copper loss depends on load current only. It is not dependent on the power factor of the load.

For a transformer power factor is dependent on load, which is variable. Hence fixed quantity VA is used in place of watts.

apparent power(KVA) is the total power from the supply, active power(KW) is the usefull power at load.

apparent p(S)=active p(P)+reactive p(Q)
s=kva=i*v
p=i*vcos@=i*V power factor=s*power factor

Actually 1.) India depends 50hz,becaz Britishers designed as per there country standards. 2) In our market major electric/electronics all are works in funda. 3) Economy of generation,transportation's ...

I completely agree to the above answers saying the 50Hz frequency is put for a common operating frequency for all electrical equipments to work at. Also our steam turbines which are major part of Ind...

X/R ration means (line reactance/line resistance) for short transmission lines it is X/R3.0 because long lines length of transmission line is due to this inductance is more(L directly proportional to...