The ac bridge shown in the figure is used to measure the impedance $$Z.$$ If the bridge is balanced for oscillator frequency $$f=2$$ $$kHz$$, then the impedance $$Z$$ will be

A $$230V,$$ $$50Hz,$$ $$4$$ pole, single phase induction motor is rotating in the clockwise (forward) direction at a speed of $$1425$$ $$rpm.$$ If the rotor resistance at standstill is $$7.8\,\,\Omega ,$$ then the effective rotor resistance in the backward branch of the equivalent circuit will be

A synchronous motor is connected to an infinite bus at $$1.0p.u$$ voltage and draws $$0.6$$ $$pu$$ at unity power factor. Its synchronous reactance is $$1.0$$ $$pu$$ and resistance is negligible.

Keeping the excitation voltage same, the load on the motor is increased such that the motor current increases by $$20\% $$. The operating power factor will become

A synchronous motor is connected to an infinite bus at $$1.0$$ $$p.u$$ voltage and draws $$0.6$$ $$pu$$ at unity power factor. Its synchronous reactance is $$1.0$$ $$pu$$ and resistance is negligible.

The excitation voltage and load angle will respectively be