Electrical Machines Objective Questions – Set 2

In DC machines shape of net flux density is?

What is/are the necessary conditions for voltage build up in self excited generator?

Flux density under trailing pole tips in case of generator will

Demagnetization effects which of the following?

Compensating winding is placed in the

Brushes are always placed on--------------- , in order to achieve sparkles commutation?

Which of the following is/are the methods to reduce the armature reaction and its effects?

The functions of inter poles are

Which of the following is/are the advantages of carbon brush over the copper brush?

Dummy coils are used for

Which of the following statements is/are correct ?

Direction of the current in the compensating winding is________ to the direction of current in the armature conductors?

Series generators are used in which of the following applications?

Which of the following is/are effects of armature reaction?

Series field consists of--------number of turns and ---------- conductors respectively

Find the reactance voltage when current is changed from -2A to 2A in 4 sec and self inductance is 1H?

Flux density under leading pole tips in case of generator will

The effect of ------------------ on main field flux is armature reaction?

Armature flux is.............with respect to main field flux or main field poles?

In DC machine torque depends on which of the following?

In DC machine shape of main field flux distribution is?

Which of the following generators are used in arc welding?

Shunt field of DC generators consists of--------number of turns and ---------- conductors respectively

For a dc machine shunt resistance and armature resistance values are

The size of inter pole are small as compared to main poles. What is the reason?

In DC machine shape of armature MMF wave is?

A 4 pole lap wound dc generator has 4 brushes, if one of the brush is damaged, what will be the change in V, I and P ratings

No load saturation characteristics are plotted between

Cross magnetization effects which of the following?

In DC machines internal characteristics are plotted between