Electrical Engineering Interview Questions

In case of single phase induction motor the stator has two winding- main winding and auxiliary winding . both of them are supplied by same source, to make a phase difference between them we use a capa...

We can use two capacitor in single phase induction motor.One in series of starting winding(to improve the starting torque so that they become self start) and 2nd is in series of running winding to improve the power factor.

The secondary winding of the tmer will burn as there is no back emf in the primary winding of the tmer.

transformer works on the principle of mutual induction which means rate of change of current or charges induces e.m.f.. hence alternating current is the one in which current varies with respect to tim...

in transformer emf is induced in primary or secondary due to self inductance & mutual inductance.flux is due to the self inductance is known as leakage flux,because it doesn't participate in transfer the energy from primary winding to secondary winding .

As the transformer rating depends on cooling system and better cooling system gives higher rating of transformer. Heat caused by the losses occurred in the transformer and losses depends on both volt...

since core loss depend on voltage and copper loss depend on current .so,product of these two is volt ampere.
it is independent of load power factor

If the load in a transformer will change then the copper loss also change because the current in transformer also change. Poh=I^2=KVA^2 this expression show that iron loss and core loss...

Nothing will happen because current will not flow through a man while he is in the air. and air is an insulator.

Nothing will happens. Because when you touch a phase wire with both of your hands and you being in air,your two hands are at same potential and no current will pass through you and you will be safe.
Since you were in air,there is no chance for current to discharge though you to ground.

Tube contains vacuum. to make conduction though it we need a kilo volts of electricity. so a normal 230v can not start conduction through the vacuum inside it. so we use the principle that when ever a...

The main function of Choke in tube light ckt is to boosting the voltage level & starter has nothing but a simple bi metallic strip inside which closes & opens the ckt.when we switch the ckt current fl...

The main reason is from the mechanical side. for better and optimal use of mechanical energy, scientists proposed that the speed of the turbine must be 3000 to 3600 rpm some countries like India opted...

It is fixed as a standard frequency considering proper utilization ,transmission and distribution of electrical power..... Even at high frequency losses will be more...which is undesirable from e...

As we know the main function of transformer is to transfer power from one ckt to another ..so ratio will same on both side of transformer..it only change the ratio of voltage and current .

Power is same, so the ratio is 1:1

single phase induction motor is not the self starting so, to make it self start we can use capacitor & capacitor also provides high starting torque.

According to double revolving theory net torque produce in single phase induction motor is 0. So we use a capacitor this capacitor creates phase difference because of leading component of current in o...

DC generator although produces a.c,it must be converted to d.c by rectifiers in order to store in the batteries and to it supply must be dc,so in cars instead dc generators alternators are used.

An alternator is more reliable than a dc generator as it doesn't have commutators and brushes. 3 phase alternator gives a much smoother output than a single phase one when rectified. Now-a-days alternators have totally replaced dynamos (dc generators) in automobiles.

In simple terms,Current is nothing but flow of charged particles which are electrons but where as voltage is the potential of that charged particles.

hi........
the main difference b/w current and voltage that the voltage is force which forced to flow the electron when the electron are starts to flow then this flow of electron is called as current.

actually there are no such difference between earthing and grounding. Earthing word we use with our installation equipments in domestic as well as in substation,grid etc. And if due to some fault occu...

Like bttu said, there is no difference between them and you can also add bonding to the group. earthing is basically used in britain and few commonwealth countries while grounding is used in america.

Q point means the quiescent point its depend upon the collector current when collector current is stable then it is stable its can be find from load line diagram where AC load line and DC load line intersect its called q point...

Q POINT is the point where a device can operate with 100 % efficiency, so for transformer energy is required for activation of its magnetic field in the form of iron loss.

The maximum voltage applied on transformer so that it can withstand without any damage (insulation, winding breakage etc.)

The current flow is dependent on the magnitude of load, when the two systems are synchronized that means you have made a single source of greater capacity so the loads will be shared by this single source and according to their respective magnitudes, that is why current flow takes place.

The primary winding of transformer oppose the current in two way that is by 1.the resistance of the wire and depends upon the material length and cross section and 2.by the inductance of a coil(primar...

Give DC supply of the transformer the DC supply is the constant magnitude. Does not operate on the transformer. The reason for XC Xl is the reluctance and one of the resistance. DC supply frequency ...

The Salient pole alternator because of its large diameter and short axial length takes more time to complete one revolution for a pair of poles under a coil, so the frequency of induced emf which is p...

Salient pole rotor has larger diameter than cylindrical rotor. In thermal power plant rotor should rotate in high speed so that salient pole will unstable due to larger diameter so that we cant use salient pole in thermal power plant.

It maintain stability of the system
...as well as voltage level.reduction in reactive power will not supply rated power to the load ....motor etc..interesting point is that capacitor... and inductor always work on reactive power .....

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.