The following measurements are obtained on a single phase load: $$V = 220 V$$ $$ \pm $$$$1$$%. $${\rm I}$$$$= 5.0$$ $$A$$ $$ \pm \,1$$% and $$W=555$$ $$W$$ $$ \pm \,2$$%. If the power factor is calculated using these measurements, the worst case error in the calculated power factor in percent is _________. (Give answer up to one decimal place.)

The load shown in the figure is supplied by a $$400$$ $$V$$ (line-to-line) $$3$$-phase source ($$RYB$$ sequence). The load is balanced and inductive, drawing $$3464$$ $$VA.$$ When the switch $$S$$ is in position $$N$$, the three watt-meters $${W_1},\,{W_2}$$ and $${W_3}$$ read $$577.35$$ $$W$$ each. If the switch is moved to position $$Y,$$ the readings of the watt-meters in watts will be:

The slope and level detector circuit in a CRO has a delay of 100 ns. The start-stop sweep generator has a response time of 50 ns. In order to display correctly, a delay line of

Two parallel connected, three-phase, $$50Hz,$$ $$11kV,$$ star-connected synchronous machines $$A$$ and $$B,$$ are operating as synchronous condensers. They together supply $$50$$ $$MVAR$$ to a $$11$$ $$kV$$ grid. Current supplied by both the machines are equal. Synchronous reactances of machine $$A$$ and machine $$B$$ are $$1\,\,\Omega $$ and $$3\,\,\Omega ,$$ respectively. Assuming the magnetic circuit to be linear, the ratio of excitation current of machine $$A$$ to that of machine $$B$$ is ____________. (Give the answer up to two decimal places).