Synchronous Generator Objectives Part 06

101 . Two alternators are running in parallel. If the field of one of the alternator is adjusted, it will change its power factor

102 . A generator is operating by itself supplying the system loads. The reactive power supplied by the generator will depend on the amount demanded by the load

103 . Which of the following part plays important role in over speed protection of a generator ? Governor

104 . Which type of protection is provided on a generator to protect against stator insulation failure Differential protection

105 . Which relays comes into operation in the event of the failure of prime mover connected to ihe generator Reverse power relay

106 . In alternators, the distribution factor is defined as the ratio of emfs of distributed winding to connected winding

107 . One of the advantages of distributing the winding in alternator is to improve voltage waveform

108 . In case of a uniformly distributed winding, the value of distribution factor is 0.995

109 . The advantage of a short pitch winding is suppression of harmonics

110 . Two alternators are connected in parallel. Their kVA and kW load share can be changed by changing respectively their excitation and driving torque

111 . In case of alternators, the dark and bright lamp method is used for synchronizing

112 . The advantage of using short pitched windings in an alternator is that it reduces the total voltage around the armature coils

113 . For the same power rating, an alternator operating at lower voltage will be larger in size

114 . Which of the following is the common synchronous speed in rpm between 60 Hz and 50 Hz alternators? 600

115 . All of the following losses for a synchronous machine are fixed EXCEPT Copper loss

116 . Salient pole type rotors as compared to cylindrical pole type are larger in diameter and smaller in axial length

117 . In a synchronous machine, the field flux axis is ahead of the armature field axis in the direction of rotation, the machine is working as synchronous alternator.

118 . Which of the following is not a common synchronous speed in rpm between a 50 Hz and 25 Hz alternator ? 200

119 . The effective voltage in one phase of an alternator having 240 turns per phase, frequency of 60 Hz and flux per pole of 2.08 x 106 lines will be 1330 V

120 . The maximum current that can be supplied by an alternator depends on strength of the magnetic field