Electrical Engineering Mcqs Practice Test

Question 1

The value of exciting or magnetizing current depends upon which of the following factors ?

Accepted Answer

D. All of the above

Question 2

By which of the following methods the temperature rise of windings and other parts may be determined  ?

Accepted Answer

D. Any of the above

Question 3

Which of the following methods is used for air cooling of turbo-alternators  ?

Accepted Answer

D. All of the above

Question 4

The slot leakage can be calculated by making which of the following assumptions  ?

Accepted Answer

D. All of the above

Question 5

Which of the following methods does not take into account the maximum temperature rise under variable load conditions  ?

Accepted Answer

C. Method of average losses

Question 6

The time taken by the machine to attain 0.632 of its final steady temperature rise is called_____________?

Accepted Answer

A. heating time constant

Question 7

With direct water cooling it is possible to have ratings of about_____________?

Accepted Answer

D. 600 MW

Question 8

In self cooled motors the cooling time constant is about ___________ than the heating time constant because cooling conditions are worse at standstill?

Accepted Answer

A. 2 to 3 times greater

Question 9

Direct water cooling of rotor winding presents_____________?

Accepted Answer

C. greater mechanical difficulties

Question 10

In direct cooled system using hydrogen both stator and rotor conductors are made____________?

Accepted Answer

B. hollow

Question 11

The resistivity of water should not be less than_____________?

Accepted Answer

D. 2000 Q m

Question 12

Machines cooled by direct cooling method may be called_____________?

Accepted Answer

D. any of the above

Question 13

The density of hydrogen is __________ times the density of air?

Accepted Answer

A. 0.07

Question 14

Which of the following is an advantage of hydrogen cooling  ?

Accepted Answer

E. All of the above

Question 15

The heated parts of an electrical machine dissipate heat into their surroundings by which of the following modes of heat dissipation  ?

Accepted Answer

D. All of the above

Question 16

The noise produced by a ___________ cooled machine is less as the rotor moves in a medium of smaller density?

Accepted Answer

B. hydrogen

Question 17

The thermal conductivity of hydrogen is _____________ times that of air?

Accepted Answer

D. 7

Question 18

cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall______________?

Accepted Answer

A. Direct

Question 19

With conventional hydrogen cooling it is possible to increase the rating of a single unit to___________?

Accepted Answer

C. 200 MW

Question 20

Hydrogen has a heat transfer co-efficient __________ times that of air?

Accepted Answer

A. 1.5