A. is always present
B. is always absent
C. may be sometimes present
D. none of the above
Related Mcqs:
- A separately excited generator as compared to a self-excited generator_____________?
A. is amenable to better voltage control
B. is more stable
C. has exciting current independent of load current
D. has all above features - Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A and B will be_______________?
A. 2 : 3
B. 3 : 1
C. 3 : 2
D. 1 : 3 - The e.m.f. induced in the armature of a shunt generator is 600 V. The armature resistance is 0.1 ohm. If the armature current is 200 A, the terminal voltage will be_____________?
A. 640 V
B. 620 V
C. 600 V
D. 580 V - Armature reaction in a generator results in_____________?
A. demagnetisation of leading pole tip and magnetisation of trailing pole tip
B. demagnetisation of trailing pole tip and magnetisation of leading pole tip
C. damagnetising the center of all poles
D. magnetising the center of all poles - As a result of armature reaction, the reduction in the total mutual air gap flux in a D.C. generator is approximately______________?
A. 40 percent
B. 25 percent
C. 10 percent
D. 5 percent - The series field of a short-shunt D.C. generator is excited by_______________?
A. external current
B. armature current
C. shunt current
D. load current - If a self excited D.C. generator after being installed, fails to build up on its first trial run, the first thing to do is to______________?
A. reverse the field connections
B. increase the field resistance
C. increase the speed of primemover
D. check armature insulation resistance - The terminal voltage of a series generator is 150 V when the load current is 5 A. If the load current is increased to 10 A, the terminal voltage will be____________?
A. 150 V
B. less than 150 V
C. greater than 150 V
D. none of the above - For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f___________ ?
A. Lap winding
B. Wave winding
C. Either of A. and B. above
D. Depends on other features of design - The armature of D.C. generator is laminated to_______________?
A. reduce the bulk
B. provide the bulk
C. insulate the core
D. reduce eddy current loss
