1. Salient pole type rotors are
a) smaller in axial length
b) larger in axial length
c) smaller in diameter
d) larger in diameter and smaller in axial length
ans. d
2. The advantage of using short pitched winding in an alternator is that it
a) reduces harmonics in generated emf
b) saves copper used in the winding
c) give the better shape to the waveform
d) all of these
ans. d
3. The emf generated in an alternator depends upon
a) coil span factor
b) frequency
c) flux per pole
d) all the above three
ans. d
4. The conditions for running two alternators in parallel are
a) terminal voltage should be same
b) frequency should be same
c) phase sequence should be same
d) all the above three
ans. d
5. The alternators are operated in parallel because
a) it is convenient and economical in repairing
b) it maintains better stability of supply
c) it is easy to install an additional unit as and when required
d) all the above three
ans. d
6. Different methods of synchronising the alternators generally used are
a) dark and bright lamp method
b) stroboscopic method
c) dark lamp method
d) both a and b are correct
ans. d
7. when two alternators are running in parallel , if prime-mover of one of the alternators is disconnected, that alternator will
a) stop running
b) run as synchronous motor
c) run as generator
d) none of these
ans. b
8. Two alternators are running in parallel. If the driving force of both the alternators is changed, this will result in change in
a) frequency
b) back emf
c) generated voltage
d) all the above
ans. a
9. The frequency per revolution in an alternator is equal to
a) number of poles
b) no of armature conductors
c) number of pairs of poles
d) none of these
ans. c
10. For a full pitch winding , the generated voltages in both coil sides are
a) exactly in phase
b) in quadrature
c) exactly 180 degrees out of phase
d) approx. 180 degrees out of phase
ans. a
a) smaller in axial length
b) larger in axial length
c) smaller in diameter
d) larger in diameter and smaller in axial length
ans. d
2. The advantage of using short pitched winding in an alternator is that it
a) reduces harmonics in generated emf
b) saves copper used in the winding
c) give the better shape to the waveform
d) all of these
ans. d
3. The emf generated in an alternator depends upon
a) coil span factor
b) frequency
c) flux per pole
d) all the above three
ans. d
4. The conditions for running two alternators in parallel are
a) terminal voltage should be same
b) frequency should be same
c) phase sequence should be same
d) all the above three
ans. d
5. The alternators are operated in parallel because
a) it is convenient and economical in repairing
b) it maintains better stability of supply
c) it is easy to install an additional unit as and when required
d) all the above three
ans. d
6. Different methods of synchronising the alternators generally used are
a) dark and bright lamp method
b) stroboscopic method
c) dark lamp method
d) both a and b are correct
ans. d
7. when two alternators are running in parallel , if prime-mover of one of the alternators is disconnected, that alternator will
a) stop running
b) run as synchronous motor
c) run as generator
d) none of these
ans. b
8. Two alternators are running in parallel. If the driving force of both the alternators is changed, this will result in change in
a) frequency
b) back emf
c) generated voltage
d) all the above
ans. a
9. The frequency per revolution in an alternator is equal to
a) number of poles
b) no of armature conductors
c) number of pairs of poles
d) none of these
ans. c
10. For a full pitch winding , the generated voltages in both coil sides are
a) exactly in phase
b) in quadrature
c) exactly 180 degrees out of phase
d) approx. 180 degrees out of phase
ans. a
