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
In a separately excited generator supplying rated load the armature reaction.
(A) is always present
(B) is always absent
(C) may be sometimes present
(D) none of the above
For both lap and wave windings, there are as many commutator bars as the number of_____________?
(A) slots
(B) armature conductors
(C) winding elements
(D) poles
Wave winding is composed of_______________?
(A) any even number of conductors
(B) any odd number of conductors
(C) that even number which is exact multiple of poles + 2
(D) that even number which is exact multiple of poles
The number of armature parallel paths in a two-pole D.C. generator having duplex lap winding is______________?
(A) 2
(B) 4
(C) 6
(D) 8
In a D.C. generator:___________________?
(A) external resistance = internal char-acteristic – armature reaction
(B) internal characteristic = magnetisation characteristic – ohmic drop
(C) external characteristic = magnetisation characteristic – ohmic drop – armature reaction
(D) magnetisation characteristic = external characteristic
In a D.C. generator the critical resistance can be increased by_____________?
(A) increasing its field resistance
(B) decreasing its field resistance
(C) increasing its speed
(D) decreasing its speed
Which generator would you prefer for feeding long D.C. transmission lines ?
(A) Series generator
(B) Shunt generator
(C) Over compound generator
(D) Flat compound generator
Following energized winding of a D.C. machine should not be opened as it would produce high inductive voltage which may be dangerous to personnel and may cause its own insulation failure.
(A) Series field
(B) Compensating field
(C) Inter pole field
(D) Shunt field
The essential condition for parallel operation of two D.C. generators is that they have ________________?
(A) same kW rating
(B) the same operation r.p.m.
(C) the same drooping voltage characteristics
(D) same percentage regulation