The armature of a single phase alternator is completely wound with T single turn coils distributed uniformly. The induced voltage in each turn is 2 Volts (rms). The emf of the whole winding is

A single-phase alternator has a synchronous reactance of $$2$$ $$ohms$$ and negligible resistance. If it supplies $$10$$ $$A$$ to a purely capacitive load at $$200V,$$ then generated $$e.m.f$$ will be ... $$V$$ and the regulation will be ...... $$\% $$

Two $$550$$ $$kVA$$ alternators operate in parallel to supply the following loads
$$(i)$$ $$250$$ $$kW$$ at $$0.95$$ power factor lag
$$(ii)$$ $$100$$ $$kW$$ at $$0.8$$ power factor lead one machine is supplying $$200kW$$ at $$0.9$$ power factor lag. The power factor of the other machine must be

A synchronous motor operates at $$0.8$$ $$p.f.$$ lagging. If the field current of the motor is continuously increased

$$(1)$$ the power factor decreases upto a certain value of field current and thereafter it increases
$$(2)$$ the armature current increases upto a certain value of field current and thereafter it decreases
$$(3)$$ the power factor increases upto a certain value of field current and thereafter it decreases
$$(4)$$ the armature current decreases upto a certain value of field current and thereafter it increases. From these the correct one is