DC Motors MCQs

Question 1

For most of the applications

Accepted Answer

dc shunt generator is more popular than dc series generator

Answer

dc series generator is more popular than dc shund generator

Answer

both dc series and shunt generators are equally popular

Answer

dc compound generator is most popular

Question 2

Equalizer connections are required when paralleling two

Accepted Answer

compound generators

Answer

bipolar genearators

Answer

shunt generators

Answer

series generators

Question 3

In case of parallel operation of compound generators, for proper division of load from no load to full load, it is essential that

Accepted Answer

the regulation of each armature should be the same

Answer

their series field resistances should be equal

Answer

their ratings should be equal

Answer

none of these

Question 4

A series generators is provided with diverter and is delivering its rated current. If the diverter switch is opened, the terminal voltage

Accepted Answer

will increase

Answer

will decrease

Answer

will remain the same

Answer

may increase or decrease

Question 5

In Hopkinson test on two shunt machines

Accepted Answer

the field current of the generator is more than that of motor

Answer

the field currents of the two machines are equal

Answer

the field current of the generator is less than of motor

Answer

none of these

Question 6

Critical resistance of dc generator is proportional to

Accepted Answer

N

Answer

1/N2

Answer

1/N

Answer

N2

Question 7

In separately excited dc generator supplying rated load, the armature reaction

Accepted Answer

is always present

Answer

is always absent

Answer

may be sometimes present

Answer

none of these

Question 8

72. With flux remaining constant, if the speed of a shunt dc generator is doubled, its generated emf

Accepted Answer

doubles

Answer

becomes half

Answer

remain unchanged

Answer

become 4 times as large

Question 9

The armature reaction ofan unsaturated dc machine is

Accepted Answer

cross-magnetising

Answer

nonmagnetising

Answer

magnetizing

Answer

demagnetizing