A resistance is measured by the voltmeter- ammeter method employing d.c. excitation and a voltmeter of very high resistance connected directly across the unknown resistance. If the voltmeter and ammeter readings are subject to maximum possible errors of $$ \pm 2.4\% $$ and $$ \pm 1.0\% $$ respectively, then the magnitude of the maximum possible percentage error in the value of resistance deduced from the measurement is nearly

In a dual slope integrating type digital voltmeter the first integration is carried out for $$10$$ periods of the supply frequency of $$50Hz.$$ If the reference voltage used is $$2V,$$ the total conversion time for an input $$1$$ $$V$$ is _________ sec

Figure depicts the load characteristics of an constant speed. Match the following sets of operating conditions with the given characteristics. Disregard the effects of saliency, saturation and stator resistance.

$$(a)$$ Constant excitation and non-zero leading power-factor
$$(b)$$ Constant excitation and zero power-factor, leading
$$(c)$$ Constant terminal voltage and zero power-factor, leading
$$(d)$$ Constant terminal voltage and non-zero leading power-factor

The developed electromagnetic force and or torque in electro $$-$mechanical energy conversion systems act in a direction that tends