**71. Regulations of an alternator supplying resistive or inductive load is**

- always positive
- always negative
- either of the above or zero
- none of the above

**72. A leading pf load on an alternator implies that its voltage regulation shall be**

- positive
- negative
- zero
- any one of these

**73. The effect of leading power factor on the voltage regulation of an alternator is**

- increasing in nature
- decreasing in nature
- maintained at constant value
- oscillating in nature

**74. The leakage reactance of a three phase alternator is determined by performing**

- open circuit and zero power factor tests
- zero power factor test and slip test
- open and short circuit tests
- short circuits and slip test

**75. The regulation obtained by synchronous impedance method is always higher than actual value because**

- synchronous reactance is assumed variable while it is not
- effective armature resistance is assumed constant
- synchronous reactance is assumed constant while it is not
- field current is increased to give short circuit current about twice of full load current

**76. The short-circuit characteristic of an alternator is**

- always linear
- always non-linear
- either (1) or (2)
- none of these

**77. Under short-circuit conditions, the power factor of an alternator is**

- unity
- almost zero lagging
- almost zero leading
- none of the above

**78. The zero power factor characteristics for the potier diagram can be obtained by loading the alternator using**

- lamp load
- synchronous motor
- water load
- dc motor

**79. Modern alternators are designed to have poor regulation as it**

- increases the value of short-circuit current
- limits the value of short-circuit current
- increases the efficiency of operation
- both (1) and (3)

**80. The phasor diagram of ASA method gives**

- reliable results for both regulation and power angle of a salient pole synchronous generator.
- reliable result for power angle but erroneous result for regulation.
- reliable result for regulation but erroneous result for power angle.
- erroneous results for both regulation and power angle of a salient-pole synchronous generator.