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 250 V dc shunt machine has armature circuit resistance of 0.6 $$\Omega$$ and field circuit resistance of 125 $$\Omega$$. The machine is connected to 250 V supply mains. The motor is operated as a generator and then as a motor separately. The line current of the machine in both the cases is 50 A. The ratio of the speed as a generator to the speed as a motor is ____________.