Q.1:
A D.C. generator works on the principle of____________?7
A.
Lenzs law
B.
Ohms law
C.Faradays law of electromagnetic induction,
D.
none of the above
Q.2:
A series generator can self-excite:______________?2
A.
only if the load current is zero
B.only if the load current is not zero$
C.
irrespective of the value of load current)
D.
none of the above
Q.3:
The open circuit voltage of a compound generator is 250 V. At full load the terminal voltage____________?i
A.
will be less than 250 V
B.
will always be 250 V
C.may be greater or less than 250 V!
D.
none of the above
Q.4:
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
Q.5:
A shunt generator can self-excite:_________________?4
A.only if the resistance of the field circuit is less than critical valueG
B.
only if the resistance of the field circuit is greater than critical valueJ
C.
irrespective of the value of the resistance in the field circuit@
D.
none
Q.6:
With a D.C. generator which of the following regulation is preferred ?F
A.
100% regulation
B.
infinite regulation
C.
50% regulation
D.1% regulation
Q.7:
Two D.C. shunt generators, each with armature resistance of 0.02 ohm and field resistance of 50 ohm run in parallel and supply a total current of 1000 amperes to the load circuit. If their e.m.fs. are 270 V and 265 V, their bus bar voltage will be_____________________?
A.
270 V
B.267.5 V
C.
265 V
D.
257.4 V
Q.8:
The essential condition for parallel operation of two D.C. generators is that they have ________________?i
A.
same kW rating
B.
the same operation r.p.m.
C.the same drooping voltage characteristics)
D.
same percentage regulation
Q.9:
When two D.C. generators are running in parallel an equilizer bar is used______________?X
A.
to increase the series flux
B.
to increase the generated e.m.f.
C.
to reduce the combined effect of ar-mature reaction of both the machinesH
D.so that the two identical machines will pass approximately equal currents to the loadW
Q.10:
Two generators are running in parallel. One of the generators may run as motor for which of the following reasons ?s