Electrical Engineering Mcqs Practice Test

Question 1

The surge phenomenon is particularly important in case of_______________?

Accepted Answer

C. high voltage transformers

Question 2

The insulation between windings and grounded core and the insulation between the windings of the same phase is called__________________?

Accepted Answer

B. major insulation

Question 3

____________ is the common method of applying brushes to the commntator?

Accepted Answer

D. All of the above

Question 4

___________ brushes are fragile and cause excessive wear of commutator?

Accepted Answer

A. Natural graphite

Question 5

The laminations of the armature of a D.C. machine are usually ___________ thick?

Accepted Answer

D. 0.4 to 0.5 mm

Question 6

D.C. servomotors are used in______________?

Accepted Answer

A. purely D.C. control systems

Question 7

The cylindrical windings using circular conductors are used for current rating of____________?

Accepted Answer

D. upto 80 A

Question 8

Which of the following in an application of D.C. motors?

Accepted Answer

E. All of the above

Question 9

The stator of a D.C. machine comprises of_____________?

Accepted Answer

D. all of the above

Question 10

is usually used for brush rockers____________?

Accepted Answer

D. Cast-iron

Question 11

Which of the following brushes can be used for high values of current density ?

Accepted Answer

A. Metal graphite brushes

Question 12

Which of the following problem arises in D.C. motors which are fed from thyristor bridge circuits ?

Accepted Answer

E. All of the above

Question 13

In a D.C. machine the number of brush arms is _________ the number of poles?

Accepted Answer

B. equal to

Question 14

D.C. machines designed with a large value of air gap length have_____________?

Accepted Answer

C. better ventilation

Question 15

In D.C. machines the usual limit of slot pitch is________________?

Accepted Answer

D. between 25 to 35 mm

Question 16

The operation of a D.C. machine with large air gap lengths is comparatively_____________?

Accepted Answer

A. quiet

Question 17

In D.C. machines, ir order to prevent excessive distortion of field form by the armature reaction, the field mmf must be made____________?

Accepted Answer

C. large in comparison with the armature mmf

Question 18

In a D.C. machine, the value of peripheral speed should not, normally, exceed___________?

Accepted Answer

C. 30 m/s

Question 19

The weight of copper of both armature and field windings decreases with __________ in number of poles?

Accepted Answer

A. increase

Question 20

In a D.C. machine the current per brush arm should not be more than_____________?

Accepted Answer

D. 400 A