The saw-tooth voltage waveform shown in the figure is fed to a moving iron voltmeter. Its reading would be close to _______.

Two ammeters $$X$$ and $$Y$$ have resistances of $$1.2$$ $$\Omega $$ and $$1.5$$ $$\Omega $$ respectively and they give full-scale deflection with $$150$$ $$mA$$ and $$250$$ $$mA$$ respectively. The ranges have been extended by connecting shunts so as to give full scale deflection with $$15$$ $$A.$$ The ammeters along with shunts are connected in parallel and then placed in a circuit in which the total current flowing is $$15A.$$ The current in amperes indicated in ammeter $$X$$ is __________.

While measuring power of a three-phase balanced load by the two-wattmeter method, the readings are $$100$$ $$W$$ and $$250$$ $$W$$. The power factor of the load is ___________.

A $$20$$-pole alternator is having $$180$$ identical stator slots with $$6$$ conductors in each slot. All the coils of a phase are in series. If the coils are connected to realize single-phase winding, the generated voltage is $${V_1}.$$ If the coils are reconnected to realize three-phase star-connected winding, the generated phase voltage is $${V_ 2}.$$ Assuming full pitch, single-layer winding, the ratio $${V_1}/{V_2}$$ is