The dc current flowing in a circuit is measured by two ammeters, one PMMC and another electrodynamometer type, connected in series. The PMMC meter contains 100 turns in the coil, the flux density in the air gap is 0.2 Wb/m² , and the area of the coil is 80 mm². The electrodynamometer ammeter has a change in mutual inductance with respect to deflection of 0.5 mH/deg. The spring constants of both the meters are equal. The value of current, it which the deflection of the two meters are same, is ___________.

Power consumed by a balanced $$3$$-phase, $$3$$-wire load is measured by the two wattmeter method. The first wattmeter reads twice that of the second. Then the load impedance angle in radians is

In an oscilloscope screen, linear sweep is applied at the

A three phase synchronous generator is to be connected to the infinite bus. The lamps are connected as shown in the figure for the synchronization. The phase sequence of bus voltage is $$R$$-$$Y$$-$$B$$ and that of incoming generator voltage is $$R'$$ - $$Y'$$ - $$B'.$$

It was found that the lamps are becoming dark in the sequence $${L_a} - {L_b} - {L_c}.$$ It means that the phase sequence of incoming generator is